I work for a Chinese company. Is it possible to pay with UnionPay (Yinlian) cards?

I haven’t tried it myself, but it’s probably possible, depending on certain conditions. It may not work depending on the country where your UnionPay card was issued, and the club may change its payment provider—or the provider’s support for UnionPay may change. It would be best to confirm when you have your meeting. That said, anyone who gets the name “UnionPay” wrong probably doesn’t actually have a UnionPay card in the first place.