Haven't really got my finger on the pulse of music in Spain, but I do have 3 friends who play in bands. I don't think it's really what you're looking for, but here goes...
I know Steve and Robin who are both English. The band is called the Cold Hearts and they play bluegrass!
Los Cold Hearts on MySpace Music - Free Streaming MP3s, Pictures & Music Downloads
I know Armando who's the drummer. The band is called Ñaco Goñi and the Bluescavidas. They play blues and have "gigs" all over Spain and are quite well known in their circle.
Bienvenido a la web de Ņaco goņi, esta es la web oficial de Ņaco goņi, los enlaces de arriba no son de la web oficial de Ņaco goņi.
As for Spanish Spanish there are lots, but I don't know too much about it. I like Oreja de Van Gogh, El Canto Del Loco, Estopa but is probably too "pop" for many. Then there are classics like Los Secretos...