Yes. I think so. I would have just merged them, but I'm torn about which should be primary. In a sense, they have different meanings. "Payment" means the way that people get paid. "Payments" are the things people use to accomplish a payment. If it was just singular versus plural, I'd take the singular as primary.
I think "payment" should be primary. First, it's the singular, which is preferred over the plural. (Just as questions about cars should be tagged "car".) And second, it also includes mechanisms for payment and not just the payments themselves. If nobody has a good counter-argument, I'll merge them this way. Everything now tagged "payments" will become "payment".
Note: Anyone with sufficient rep can propose/upvote the merge. You'll get extra rep for your trouble. And if enough of you do it, then this question will become academic. (And while I can't propose it, I can upvote it! So if someone else proposes it, then I get extra rep if I upvote it before I do it. Go figure.)