MsMe, you are incorrect, look at the posts above, Blue Shield actually has easier criteria.
However, with a BMI of 35, that's right on the brink of being too low.
Anyone who has a Clifornia HMO plan can get their health plan's criteria for the surgery (or anything else) in writing on request. Most of them are available online, just Google your health plan name and the kind of procedure.
In some cases, (again, in CA, HMO coverage), your medical group may have their own guidelines. In that case, be armed with your health plan's criteria. Usually if you point out that your health plan uses different criteria, they will use the plan criteria. This is because the plan will overturn on appeal a decision that doesn't conform to their criteria.