We have bathed Toto as often as we want from day one! Our breeder had just bathed her when we brought her home and she was just so sweet and smelled so good, it really spoiled us and we can't bear for her to smell like a "dog"!
When we realized that we wanted to bathe her more often than all the books suggested, we discussed it with our vet ... Dr. Lucy said we could bathe her as much as we wanted as long as we don't see any problems with her skin or coat! So ... if it's once a week ... every other day ... we do it as often as she needs it! So far, so good ... no problems! I always make sure that I rinse her for a long time using a good sprayer. I take all her "equipment" along when we are travelling ... if a hotel doesn't have proper bath equipment ... Patrick does!!
I think for the most part, it's whatever works for you and how much time and energy you want to dedicate to your baby!!