It's likely not Bikram. Bikram is one of the more common forms of yoga that's going around right now, based on the concepts by Bikram Choudhury. I doubt it's been around that long, since Bikram himself is still teaching. One of the main features of Bikram yoga is the heat of the classroom. It's HOT, 100 to 105 degrees F, so you drink a lot of water before hand and then promptly sweat it all out, which is supposed to be cleansing. (It actually does make a noticeable improvement on my skin when I'm going often enough).
Headstands? Those are hard! I still can't do them.
Thankfully there aren't any in the classes I take.
Shoulder-stands are wearing enough on the abs after a while.
Is your class more of a "flow" style, or is it a lot of distinct separate poses?