The breeding of bees with tulips would grant the player "The Parrots and the Bats" (minecraft:husbandry/breed_an_animal) advancement, but does not affect the progression of "Two by Two" (minecraft:husbandry/bred_all_animals) advancement.

In other words, bees need to be added to the entities for minecraft:husbandry/bred_all_animals advancements.

Code analysis:

In the field "a" of type "[Lajs;" in "gp" class (list of entity types in the husbandry tab generator), the field "e" of type "Lajs;" from "ajs" class (bee entity type constant field) should be added so that the generated minecraft:husbandry/bred_all_animals advancement will include the bees in its criteria.