Its pretty simple.
These 'super pheromones' should heighten sexual urges. So for a gay man/woman that would still attract them to the same gender of Deltan that they have always been attracted to.
That depends on how the pheromones work. If they are "merely" aphrodisiacs, what you say is correct. But if they work like Orion pheromones, ie working on specific sexes, then things would be different (though even then, it depends on just what the mechanism the pheromones use to get the reaction, and what specifically causes the homosexuality in the human).