If you continue to apply for a credit card in another bank, you can't apply for a card business with one card, because every bank has some requirements for the credit card you hold. I suggest that you don't apply for a credit card continuously, as long as your credit limit is enough. Moreover, if you handle multiple credit cards in the same bank, the credit line is shared, but each card needs to pay an annual fee, which is not cost-effective.
I hope my answer can help you. You can also call the customer service phone of the bank for consultation.