Is Supernatural: Tribes o Supernatural: Bloodlines the name of the spinoff series. I heard both, but don't know the official.

It was Tribes but then renamed Bloodlines :)

bloodlines because tribes was a horrible name

there is a rumor that this mostra isn't getting made i hope it isn't because as a spin off from Supernatural judging from the episode it was introduced it would suck its way much like vampire diaries not Supernatural but i do think it would do better as a stand alone show