I'm curious to hear about what you discover, as my wife and I constantly discuss relocating to San Antonio, which I might add is a lovely city!
That being said, I don't know any specific providers there, but I do know there is a support network which may be able to better direct you. San Antonio does not have the same resources as the GEAR center in Dallas but after looking into SAGA, they listed an FNP who does hrt.
http://www.nursepractitionerassociates.com/Also, my former endo relocated his practice to New Braunfels, so there has to be nearby options... Worst comes to worst, Austin has a good deal of transinclusive endocrinologists.