I have a candy cookbook that was published in 1953. They differentiate between bob bons and chocolates, and what they call bon bons are what I think of them being.
The filling in a bon bon is creamy, and is flavored with vanilla or some fruit flavor. Rather than being dipped in chocolate, they are dipped in fondant which has been colored a pastel shade and indicates the flavor – so a pale yellow bon bon has an lemon-flavored filling.
The book makes a point of saying that some bon bons in the box of candy you’re giving to someone adds a lot of visual interest to the assortment
I don’t know if they are the same thing (I never saw them at the movies), but I have a box of Trader Joe’s Chocolate Bon Bons in the freezer. They sound like what you are describing and are delicious.
As a generic term, bon bon, for me, doesn’t refer to anything specific at all. It’s like “sweets.”
Yeah, I’m aware of trademark uses of the term, but they vary so much, it’s clear that the term itself isn’t fixed.
In English, its generic use is pretty much old-fashioned. I hear it more currently in its Spanish figurative equivalent, bombón, (Esa pelada es un bombón, etc.)