There is something going on on the Avenida 6 almost every night. It is just few blocks from The Iguana Hostel. On Friday and Saturday you can drink and dance almost in every corner of Cali. All parties in the City finish at 1-2am. After midnight the party crowd goes to the clubs of Menga or Juanchito where you can party until 5am. If you take a taxi from The Iguana Hostel it will cost you about 8000P (10min) if you go to Menga and up to 15000P (15-20min) for Juanchito.
Chango in Juanchito
Las Brisas de Jamundí - Km 7 Vía Cali-Jamundí, taxi about 15000COP one way
Siboney in Menga (couples)
De Melodías en la Roosvelt
La Bodega Cubana
Parque de la Caña
Also check Salsa PDF guide from Cali