I don't think all is equal per say... For example, I think some therapists will be better at eliciting strong transference reactions from you period. You will just feel closer and more related to certain people, like we all do. If your problem is your mother you might have trouble trusting a female T, or conversely maybe a female T will best remind you more of a mother figure, it really can be different for everyone. Just the same you can have maternal transference feelings for a male T, but just because you can have transference for either gender doesn't mean they are equal though. Each transference will be different depending on the chemistry and mix of your personality and history, with the therapists personality and history.

The reason it's possible to have these feelings is because they are related to unconscious needs for things like love and security, and both men and women can offer that.