Haitian culture is generally pretty tolerant of male and female homosexuality. While you may hear occasional jokes about masisis (gay men) or madivines (lesbians), you rarely see the kind of hatred and mob violence which is found in Jamaica or some other Caribbean islands. And there are no specific taboos within Vodou against same-sex relationships or love affairs. Indeed, gay men (particularly clean, well-dressed, polite gay men) are frequently placed under the patronage of Erzulie Freda -- I've heard it told that she likes them so much she makes them gay so that they won't be interested in any other woman. And Danto is well known to be partial to lesbians: indeed, there's at least one song that refers to "Danto Madivine" or Danto the Lesbian.
Transgender spirituality in Haiti is quite different than in the West: there's little or no access to hormones or sexual reassignment surgery, and most transgendered people will identify as "gay" or "lesbian." But I've seen pictures of at least one house comprised of transgendered Haitian women who lived and served the spirits as women. And there are many houses comprised largely or exclusively of gay men or lesbians.
Keep in mind that "each houngan and each mambo is king of the house" - there's considerable diversity between different houses. Those who don't get a warm welcome in one société may find another more suitable to their needs. In general, though, Vodou is a very gay-friendly tradition - so much so that it's been said that a disproportionate number of practitioners in Haiti and the Haitian Diaspora are gay.