Quite a few people keep Emp angels in SPS reefs. The angel experts on here seem to agree that angels are safe with healthy sps. Sick/dying sps may be viewed as food though. Clams are another story and you are playing russian roulette adding non-Genicanthus angels with clams, although plenty of people also do that as well.
PBT's can be nasty fish though and there could be some initial aggression, but hard to say.