I believe it's called the St. Peter's Basilica unless they've begun instituting animal sacrifices.
Somewhere in St. Peter's the church is referred to as a temple, at least according to Mother Angelica. (I saw this rerun last week).
She herself claims to have been told by the infant Jesus to "build a temple for me." She said that she was confused, because she had never heard of a Catholic temple. But one day when she was in St. Peter's, she saw that it was called a temple.
The Solomonic columns used in the high alter of St. Peter's provide converging evidence. Catholic Churches are heavily influenced by the design of Solomon's Temple.
Finally, we Christians can regard ourselves as completed or messianic Jews. So the idea of calling a church a temple should not pose too great of a problem for us.
My two cents, anyway 8-)