long response, sorry....
I have blue cross HMO and Health Net HMO. I live in So Cal, too. I have called both HMOs
monthly to see if they would cover HB/MW, and they said no, no, no, no. I document every call. The only reason was becuase there was no MW in my network. So they DO cover the midwife care (probably not the HB), and I think I've got a fighting chance at getting something back becuase they cover midwives in other areas. They won't cover me becuase my stupid primary care doctor won't refer me out of the system to a local MW, and the closest MW within the HMO system is over an hour away (the HMO's won't cover prenatal services outside of a 50 mile radius from my house).

:
So here's what I'm doing. Today I went to the human resources office at my work and explained how unhappy I was with my benefits. They gave me the number to our benefits broker, who is apparently good in helping in these situations. I gave him a call today and am awating a response. He's going to get an earful.
Also, I am going to torment my health care provider (a big regional medical group) until they agree to refer me out of the system to a MW. It seems that, becuase of malpractice reasons, Obs in my area don't like to treat women who are also seeing midwives (this is according to my MW). In fact, they will actually dismiss us from their care. There are only three OBs employed with the medical group, so my plan is to be dismissed from every single one of them until there's no one else to refer me to within the system. It will be a long process, but heck, what have I got to loose? Once I run out of OBs, I will request that the health care provider give me the referral I want, since no one else will see me.
I know, I know, it sounds like a lot of effort and time, but I'm determined to figure out a way to beat this. Between the broker and pure determination, I hope to at least have 1/3 of my midwifery care covered.
I'll let you know if it works.