Considering that, even if you ignore that 90% of what goes to the recycling center doesn't actually get recycled, plastic recycling's value is still fairly equivocal, I think it'd be better to just make it a straight up excise tax.

Save the deposit method for the things where returning them leads to a clear win: aluminum cans and reusable bottles. That way you're encouraging reduce and reuse first.

"Recycle" was never supposed to be the first resort in waste reduction, and, at this point, it's arguably not much of a waste reduction technique at all, and instead the centerpiese of an elaborate ecological shell game.