I was mentored by a dom. I have reservations about dommes - the ones I know well either all take male subs or - if they take female subs are extremely harsh on them.

Oz's comment is interesting - however, there is no need for his mentor to have anything to do with you - and on the other hand it comes down to trust between you and your dom: if you both want a serious relationship, then you will not let another person interfere with your relationship, will you?