I believe in the book "immortal blood" others are mentioned but are very small and insignificant. correct me if i'm wrong.There is only one vampire bloodline in Cyrodiil as far as I am aware, and it will be implemented sometime in the future. I want that one to have a more secretive upscale society feel to it. For now, I am working on the Morrowind ones, but they're almost done.
I don't think I'll make any bloodline have an actual ck2 society bound to them, as there would be only a few members, and it wouldn't work that different from what it does, now. Besides, infiltrating the guilds is fun