It doesn't. It's one account that has essentially has multiple account numbers. It's the activity of the underlying account that matters, not which account number you as an end user use to access the account.

One account, one statement - but you have many numbers at your disposal. The virtual cards don't impact your credit score any differently than a traditional card product offered by any major issuer.

I really doubt that this is going to be reported as separate accounts to the credit agencies, it wouldn't make any sense.