I own some VCAIX (Vanguard Calif. Muni Bonds). I'm thinking of adding to my bond allocation. I still want the tax free variety bond fund. I'm thinking of adding more to VCAIX or to start up with VWITX (Vanguard Muni Tax Free Bonds). I think I come out ahead with the Calif bond fund, but I have concerns about having my entire tax-free bond allocation tied to one state (that be where I live, California). It seems like there's more risk with VCAIX, but I have no idea how much more risk. Any ideas on a reasonable way to go on this one?