I'm not positive in this but I believe a California Bungalow features a number of shared design elements that you will also find in Craftsman homes such as low sloping roofs, asymmetrical exterior proportions, open floor plans, roof overhangs, small porches along with a front stoop, but don't necessarily have to be in the traditional Craftsman/Arts & Crafts style.
What we call California Bungalows can share all of those general elements while being in different aesthetic styles such as Tudor or Spanish Mission. Basically, Craftsman would be a subset of the larger California Bungalow style.
