+1 for opinions above. Most traditions outside of Hermetic, Shamanic and Chaos are religions (or at least a philosophy that replaces religion). I can't see mixing two in one character. Magic is about belief, I think. If you are devoutly Christian (and for all practical purposes in SR this seems to mean Catholic), I can't see your Magic tradition following another tradition that is based off of a religion. Maybe a character who grew up Catholic, still goes to Mass to keep grandma happy, but is a closet pagan. That makes sense. But I can't see a devout Christian being Voodoo, as I imagine Christians seeing spirits as either angels or demons, and being possessed by any spirit should be totally taboo for a Christian. Because if you are a follower of Voodoo, you aren't a devout Christian, you left that for the Voudan religion.
Buuuuut, I can totally see a devout Christian being hermetic, chaos (especially non Catholic Christians) or even shamanic traditions. Shamanic would be the worst fit though, due to traditional Christian views regarding spirits, and animist religions of old.
Last thought, I can imagine a person who believes they are a devout Christian, who begins following Voodoo, and still thinks they are a Christian. The Christians would no longer agree (heretic!). Now we move into different territory...
Kind of hard to claim a religion when no one in that religion accepts you as practicing the same faith as they do.