A business credit card can affect your personal credit score if the name on the credit card is your personal name and not the name of the business.
If you are responsible for making the payment for that account then it is likely that even a business credit card is listed on your personal credit report even though the business reimburses you for the payment later. If only the business pays for the credit card then it is likely that the card appears only on the business credit report. The easiest way to find out whether a business credit card is affecting your personal credit score or not is to order a copy of your personal credit report and see if the account is listed there. If it is then, yes the business credit card and the transactions made on it are going to affect your personal credit score.