I think that Pence is as far to the alt-right as a politician can possibly be. He would likely bring a Christian fundamentalism to the white house, so if you want the Bible to be the law of the land, he’s your man.
I don’t think that necessarily makes him alt-right, though. He’s definitely very far right, and a more than a bit of a theocrat, but I can’t recall him doing or saying anything that makes me think he’s a white nationalist, neo-Nazi, skinhead, Klansman etc. I think the closest you could get, and it seems like a bit of a stretch to me, is him not condemning the travel ban.