Hi Dib,

Welcome to Basel. I am Brazilian and I moved to Basel just a few months ago, I guess this should be a nice place to dance Latin music:

http://www.allegra-club.ch/

Basel has a Samba School which rehearsals every Wednesday evening:

http://www.sambrasileia.ch/

I have a friend who is having Salsa and Tango lessons, she can tell you about the other Schools.

Cheers!