Is it wrong to fantasise about what you find attractive but cannot have for real ?

Having fantasies (sexual or otherwise) are pretty normal and they connect with our dreams, wishes, goals and desires.

ie. I feel that what I like about women is worth expressing through imagery, etc. but I know that my views and feelings about that are probably totally different to almost everyone elses.

Like art - beauty is in the eye of the beholder, and just because person a says that piece of art is 'priceless' to person b it might have no meaning/value and be considered worthless.

Admiring what you can't have is assessed on how you go about expressing that admiration. Providing you do it in ways that are meaningful to you personally is what matters. If another person finds it offensive and/or confronting then that person just needs to 'be like bill' and move on with their life.