Hi penumbra, I completely agree, species specific pollination is one of the incredible way evolution works. Several species of wild bees have specific plant species they pollinate, and several wild endemic flowers have specific wild bees they can be pollinated by, so they depend on each other and coevolve. Wild bees tend to be solitary or have small colonies.
European honeybees, on the other hand, tend to be a bit more generalists and have large colonies. That is why farmers keep honeybee colonies in their orchards as they are proficient pollinators. But, as you mentioned, even honeybees would visit a single flower as pollen/nectar source, but given some conditions, if it is in bloom and relatively separated from other blooms. This is mainly due to the way they direct the colony to visit the nectar/pollen source. If there are different species of plants, in particular flowering trees that are in bloom simultaneously and next to each other in a mixed crop (not a monocrop), they will visit them.