Hi Kari, I am afraid that to work as a massage therapist in a Spanish salon you will have to speak Spanish, get yourself into a course ASAP.
You could set up at home and put out a few free or cheap ads specializing in mesage therapy for the English speaking Ex-Pat community. I have seen many such ads in both InMadrid and the Broadsheet as well as Barcelona Metropolitan (all ex-pat papers here) advertising everyhting from psychiatric help to dental surgery and aimed at native English speakers, it is just crazy enough to work

I for one could use some massage therapy ASAP!
As for the Briths and American women's clubs here in Madrid that Tracy mentions, try the classifieds at
http://www.in-madrid.com/class.html, there is loads of info there for networking.
Saludos & good luck,
jer...