Call Dr. Felix in Fresno he is the Blue Cross perferred provider for California. I dont have his number handy but it is on this website under physicians.
I got approved when I went through them with Dr. Katlhouda. His staff did everything for me to get approved and it wasnt that hard. Look him up and if you cant get his information just call up USC University Hospital. Hes one of the best at what he does!
I have BC PPO and was approved on the first try, within in a couple of days. It really depends on your specific policy, but they seem to be good with WLS.
I live in Florida but my insurance is BC of CA. I went through the 6 mo. pre weight loss which was required by the insurance. Once my paperwork was submitted, I was approved in 2 days. Wishing you the best.