I think that all relationships can or cannot be places where dominant culture rule-it all depends on the individuals involved. There are heterosexual relationship that are equal and feminist in nature, and there are lesbian relationships that are unequal, violent, and reflective of dominant culture. Rockhill is searching for a space where experience has not yet been colonized by ideology and therefore she can find safety from dominant cultural norms. She argues that one such space may be lesbianism ,where the possibility of resistance may rest. Lesbianism is a space where heterosexism can be challenge.
Heterosexual women can also challenge heterosexism.
However, for women who have invested in heterosexuality it could be emotionally harder and more threatening to adopt a position of resistance.