It’s okay even if you have a visa and a master card. It depends on what kind of card you apply for. Some visa\master cards have the same characteristics as domestic UnionPay cards. Unless you have a credit card (overdraft card) or an international debit card, your card can only be used in Singapore. If you first take it home without knowing the nature of your bank card, you should tell the bank staff when applying for the card that you need a bank card that can be used in both Singapore and China.