The stricture against Tex-mex is really harsh. San Antonio has some amazing restaurants in that tradition. I can't imagine living in Texas without eating tamales at every possible opportunity. It may be that if you shop around and find places that don't fit your prior experience with Tex-Mex you can find something that will please you both and take advantage of the local area.
That being said, San Antonio actually has some pretty good Italian food, most of it is kind of chintzy, San Antonio is the home of the original Romano's Macaroni Grill, but there are also some really great places supported by the fairly sizeable and proud native Italian community. There's a really great deli I'm trying to remember the name of... ...if I find it I'll get back to you.
HEB is a great grocery store chain. The largier fancier ones offer an amazing selection for Texas chains, and feature things like Valet parking and in store samples of roasted Brie in raspberry Chipotle sauce.
I can't visit them anymore, since I discovered that I would easily drop $70 any time I walked in there, and that half of that would be spent on products from their famed wall o' cheeses.
If you have stronger will power you will probably enjoy it.
There's also good barbecue and breakfasting places. Outside of town is great German food.
