Are Bill Pay checks considered Remotely Created Checks? I have a bank trying to return bill pay checks because their customer's account was compromised. It is beyond the 24 hr period from which they can return.

If the checks aren't signed by the depositor on whose account they are drawn, they probably fit the Regulation CC definition of RCC, unless they are drawn by the drawee bank on its customer's account (as may be the case for bill-pay checks):

Remotely created check means a check that is not created by the paying bank and that does not bear a signature applied, or purported to be applied, by the person on whose account the check is drawn....

If the check fits that definition, and if the depositor on whose account it is drawn makes a claim under oath that he/she/it did not authorize the issuance of the check payable to the named payee in the amount of the check, the warranty under §229.34(d) would appear to have been breached.

I am not sure that is how the Fed intended the warranty to be applied. Generally, RCCs are understood to be deposited by their creators. In this case, it appears the check may have been "authorized" by an unauthorized third party.