I wouldn't say bisexual makes sense categorically for anyone who dislikes half of the masculinity/femininity spectrum. I mean it is a bit different with femboys, but I also suspect attraction there is very superficial (esp. if the look uses silicone body stuff) and likely wouldn't work as much in-person especially on a relationship level.
There is the term gynephilia, though I also don't expect something like that to be casually mentioned/understood/accepted. In which case, no good answer I guess.