There are definitely different 'markets' within US football fans. Many fans are getting quite knowledgeable by watching teams from different leagues but usually support Man U or Liverpool. They can know quite a few Wolves players.
American latinos in TX are not really football fans (I mean not soccer fans), unless they are Mexican Nationals - then it is very different. The Nationals all know Raul and many Spanish/Portuguese players. They usually support Madrid or Barca.
Mexico played Argentina here a few months ago and the occasion got absolutely zero coverage from the English speaking media, but was shown live on Spanish speaking TV and attracted a decent attendance, many of whom would have travelled from Mexico.
Spanish speaking tv broadcasts Mexican games every week and also Champions League.
MLS gets no mention in local media and that is unlikely to change until San Antonio gets its own team (not going to happen). There is a San Antonio team in a lower league - they occasionally advertise on tv otherwise I would not know they exist. They played Cardiff in a pre-season friendly last summer but not a single person I spoke with knew about the game.
If Man U or Liverpool were to play a game in SA then the media would cover it; if Wolves came only the Spanish speaking media would likely be interested (and would broadcast it live) but the occasion could certainly be used to help grow the sport, Premier League, and Wolves. However if Wolves went to Dallas or Houston it would be different since these are MLS cities and would attract a much larger crowd.