While ATP Flight Training has ATP in their name they don't do much ATP level training except for the Airbus type rating in DFW. Their web page says training through commercial multi engine/IR/CFI. An FO at work was separating and used the Houston location to get his ATP. He was the first person to get his ATP there. That being said the ATP ride is really just the instrument ride to a higher standard. If someone can teach the IR they should be able to teach the ATP.