Superman has one advantage over Batman aside from all the superpowers; I'm pretty sure that he knows that Batman is Bruce Wayne. In that Death of Superman aftermath, Superman asks Batman to come with him to that machine city where all the other superheroes are getting together to destroy it. He immediately recognizes that, aside from a different costume, it's not the old Batman underneath the mask, but he doesn't have time to use his x-ray vision to find out for sure.
