Install 21, and then check in the store on your ps4 and you should be able to buy Rewind on its own agreed installing 21. Please tell us the price when you do it this way, because we don't know it either.
I agree, EA made a compete mess of this release. Strong-arming people into buying an 80$ game to get rewind isn't earning them any fans. There's a reason I never buy the new games, I never play them and they're quite expensive. I have 06-13, barely played them.