I think the power dynamic of the situation you describe is different from the power dynamic between Kira and Bareil. In the case of the priest telling the young naive woman 'God said we have to sleep together', the priest has all the power and is abusing that power.
Between Kira and Bareil, Kira always had the power in the relationship. She's not a naive young woman. She is 'troubled' but not in a way that makes her vulnerable. Bareil had no power over Kira to abuse.
Also given the D'jara system where people take up the vocations of their parents, it makes sense within the Bajoran religion for priests to be able to get married.