No, I'd say that listening to a few gringos living in tourist would only paint part of a realistic picture... so read what I wrote above and consider it's from someone who first travelled here over 20 years ago and has now lived here close to 10 years. 17 of those years working alongside Dominicans and a portion of that time in Santiago as a key member in a very large Dominican employer. My exposure to the Dominican population by far is not limited to tourist areas or lower socio-economic class individuals who may be opportunists.
Attitudes have certainly changed. Also, Dominicans also believe foreigners are generally very tolerant of homosexuality and no doubt that can influence what one hears. But to say that homosexuality or bisexuality are openly accepted here or widely practiced is misleading to say the least. Just listen to a bunch of guys drinking or at the gym or whereever there is a tv on when a program like duenos de circo comes on and you will get a good idea of still traditional attitudes.