I did some checking this weekend just to be sure, and verified that there is no genre fields returned from the PMS when requesting the currently playing item... HOWEVER, it seems like you probably can pull this back via a (separate) request for the metadata of the item. I say probably because the example metadata query I have here is for video, but it lists the genre(s) for it. I'm assuming that would pull back music genres as well.
I'll do a little experimentation and see if it is something worth adding to the plugin directly or, if not, I may be able to add a helper or event or something that would allow you to pull it back via a script.
Adam