Salon-de-Provence is a commune of 40,100 people ( 2005 ) . It is found in the region Provence-Alpes-C Ã te d'Azur in the Bouches-du-Rh Ã ne department in the south of France . Salon-de-Provence is a commune in the Bouches-du-Rh Ã ne department in southern France .