Wow! I got a message on my work phone from someone who obviously didn't care...Basically Six Flags Fiesta has no gluten-free options, but we would be free to bring in snacks provided we checked in with customer relations. And, we could keep food in a cooler in the car. I don't think so! Sea World, on the other hand, seems to have some gluten-free options, and I'm sure we can find restaurants in San Antonio that will do. So, Sea World, the Alamo, and the Riverwalk will be on our itinerary. Six Flags - NOT! Just glad the call came in while I was gone from work, or the caller would have gotten an earful!
Still, would appreciate any feedback on any particularly good places in San Antonio, if you know of some.