Welcome Alqua and Galadhril! :D I don't think there are any specific references to Tom being Maiar in any of Tolkiens writings. But then again, I haven't read all of Tolkiens writings! However, there is one thing that suggests to me that he is. The elves called Tom 'Irwain Ben-adar' which I believe means 'old without a father' which suggests demi-god like or angelic roots. :angel: Since we know Tom is not Valar, that only leaves Maia. I suppose he could be something else entirely, but one would think Tolkien would have metioned such a powerful being in The Silmarillion. I guess Tom was intentionally left a mystery, but what good's a mystery without someone to wonder at it? ;)
I am no Tolkien expert though. There are other site members who are far more knowledgeable about these things than me!
WWGD: What Would Gandalf Do?