Sort of(?)

I think the main point to recognize is that when we say "price", we usually mean some average of the last traded price from various exchanges.

So in that sense, it's mostly driven by retail (or institutional traders who use the exchanges)

However, OTC and the exchanges are connected because in the end there is a single underlying stock of bitcoin, and the assets are the same. If the "price" via either OTC or exchange get too out of balance, they should get arbitraged back towards each other.