But if a company already has their own custom app for their bonus card, that means they already have the developer subscription

Yes but they are not going to sign your pass you make

	▲	what an hour ago \| parent [-]
		I’m pretty sure the idea was that they would make a pass you can add to wallet instead of installing their app, not that they would sign the random pass you made. I doubt it though because they could have already done that. My local science academy stopped printing cards, they just give you something to add to wallet.