As for the Nicolaitans I'm quite positive that they were named although not in the Bible. The reason is because they id name the leader but there was probably so many of them that it was much easier to simply name the leader and those alive then would have known who the followers of that leader were. I'm sure that if there was any doubt that it was cleared up in person. Here's more info on them: (I'm including this both for myself as a reference and for others who may not know about them)
The Nicolaitans are certainly mentioned in both Ephesus and Pergamum, and in the message to Pergamum the followers of Balaam appear to be the same people. Though neither of these names is applied to the heretics in Thyatira, the activities of the Nicolaitans/Balaamites in Pergamum are the same as those practised by ‘Jezebel’ and her devotees there: they all eat food offered to idols and indulge in practices which were regarded as immoral.
Paul had dealt with both these issues at an earlier period, though he never suggested that those involved in such activities were ‘heretics’ in the strict sense. He had declared that eating food offered to idols was a matter of indifference to Christian believers (1 Corinthians 8) and, though he typically had less patience with instances of immorality, he generally dealt with them in a tactful and generous way, seeking to persuade rather than to dictate. Things must have changed in the interim. In Paul’s time, these concerns were mainly practical issues, arising naturally as Gentile converts struggled to understand how their new faith might affect their lifestyle. But they had now become theological and doctrinal issues and, though the book of Revelation gives no real indication of the kind of beliefs that led to such activities, a number of considerations suggest that these sects were an early form of what was later known as Gnosticism:
n Members of one of the prominent Gnostic groups of the second century actually called themselves ‘Nicolaitans’. They traced their origins back to a man called Nicolaus who, according to Acts 6:5, was one of Stephen’s Hellenist colleagues in the early Jerusalem church. It is unlikely that they had any real connection with this person, but some of their practices were not dissimilar from what we read about in the book of Revelation.
n Though the heretics opposed in Revelation were undoubtedly less sophisticated and less well organized than these later groups, there are some signs of Gnostic terminology and ideas here. For instance, Jezebel’s teaching in Thyatira is referred to by John as ‘the deep secrets of Satan’ (Revelation 2:24), and this phrase is found among later Gnostic groups as a description of their own beliefs. The very fact that a woman should have been so prominent in this movement is also consistent with some kind of Gnostic connection, for in the Gnostic movements of the second-century, women often enjoyed a significant and conspicuous role. Indeed, this was one reason why the church after the New Testament period officially excluded women from any form of public service.
n The evidence of other New Testament books points in the same direction. The letters of John, as well as the letters of Jude and 2 Peter, all seem to have originated in the same geographical area as that referred to in Revelation, and in all of them there are mentions of wandering teachers who operated in the same way as those who are dealt with in Revelation. 1 John explains their theology in considerable detail, and we can see from this how close these people were moving towards classical Gnosticism.
Drane, J. W. (2000). Introducing the New Testament (Completely rev. and updated.) (448). Oxford: Lion Publishing plc.
So, let's see what 1 John says:
1 John 2:18-19 Dear children, this is the last hour; and as you have heard that the antichrist is coming, even now many antichrists have come. This is how we know it is the last hour. They went out from us, but they did not really belong to us. For if they had belonged to us, they would have remained with us; but their going showed that none of them belonged to us.
1 John 3:7-10 Dear children, do not let anyone lead you astray. He who does what is right is righteous, just as he is righteous. He who does what is sinful is of the devil, because the devil has been sinning from the beginning. The reason the Son of God appeared was to destroy the devil’s work. No one who is born of God will continue to sin, because God’s seed remains in him; he cannot go on sinning, because he has been born of God. This is how we know who the children of God are and who the children of the devil are: Anyone who does not do what is right is not a child of God; nor is anyone who does not love his brother.
1 John 4:1-6 Dear friends, do not believe every spirit, but test the spirits to see whether they are from God, because many false prophets have gone out into the world. This is how you can recognize the Spirit of God: Every spirit that acknowledges that Jesus Christ has come in the flesh is from God, but every spirit that does not acknowledge Jesus is not from God. This is the spirit of the antichrist, which you have heard is coming and even now is already in the world. You, dear children, are from God and have overcome them, because the one who is in you is greater than the one who is in the world. They are from the world and therefore speak from the viewpoint of the world, and the world listens to them. We are from God, and whoever knows God listens to us; but whoever is not from God does not listen to us. This is how we recognize the Spirit of truth and the spirit of falsehood.
Let's continue to see what John says to them in other letters as he does continue in the same theme:
2 John 7-11 Many deceivers, who do not acknowledge Jesus Christ as coming in the flesh, have gone out into the world. Any such person is the deceiver and the antichrist. Watch out that you do not lose what you have worked for, but that you may be rewarded fully. Anyone who runs ahead and does not continue in the teaching of Christ does not have God; whoever continues in the teaching has both the Father and the Son. If anyone comes to you and does not bring this teaching, do not take him into your house or welcome him. Anyone who welcomes him shares in his wicked work.
3 John 9-10 I wrote to the church, but Diotrephes, who loves to be first, will have nothing to do with us. So if I come, I will call attention to what he is doing, gossiping maliciously about us. Not satisfied with that, he refuses to welcome the brothers. He also stops those who want to do so and puts them out of the church.
In a cross reference to the above verse we have:
Philippians 3:2-4 Watch out for those dogs, those men who do evil, those mutilators of the flesh. For it is we who are the circumcision, we who worship by the Spirit of God, who glory in Christ Jesus, and who put no confidence in the flesh— though I myself have reasons for such confidence. If anyone else thinks he has reasons to put confidence in the flesh, I have more:
Philippians 3:17-19 Join with others in following my example, brothers, and take note of those who live according to the pattern we gave you. For, as I have often told you before and now say again even with tears, many live as enemies of the cross of Christ. Their destiny is destruction, their god is their stomach, and their glory is in their shame. Their mind is on earthly things.