Are the flower features chosen when bonemeal is used on a grass block determined by the datapack?

I have registered a configured feature that is not just a simple block feature, and I am trying to add it to the possible flowers that can generate when bonemeal is used on a grass block in a dark forest biome. Is that determined by a datapack? If so, how do I add that feature to only generate when bonemeal is used in a dark forest?