There are several good doctors in your area. I had my gastric bypass performed by Dr. Steven Fath of Seguin he does some clinic work out of Innova hospital in San Antonio. I do not know for sure if he takes Tricare but you could call his office ask.
Wilford Hall has doctors there. That is where I had my gastric bypass. The bariatric clinic number is 210-292-4303. They have an excellent support group as well. I wish I lived closer but it is too far for me. I will be down there on Wednesday for my 6 month appt though.