I've had fantasies about other women, but actually this hasn't been one of them, so no (well, I don't think so anyway, never say never!) and no. My woman-fantasies have revolved more around toys/threesomes.
This is a big fantasy for my wife, for a woman to go down on her. She has no interest in going down on another women, but she LOVES to receive oral. She told me she fantasizes about this a lot when she "touches herself".