Unable to join a machine with a bonded interface to satellite 6

When I try to join a machine using subscription-manager register I get this error.

HTTP error (422 - Unknown): Validation failed: Attached to can't be blank

I looked through the logs and it looks like it is unable to determine the slave nics of the bonded interface. Is there a way to specify that on the system? Like a file in /etc/rhsm/facts/?

Thanks!