I'm not so sure the boss is in violation of the Hilton T&Cs.

In the T&C, it specifically says group master-billing billed to a company or bills settled by a single individual at the time of check-out are NOT eligible for points. It sounds like the OP's situation. If the boss is using a corporate card, it may be the rooms are paid directly by the company via this card. Is the OP sure the boss is getting points or is the company "bank"?

The T&C say that if the individual is responsible for authorization of settlement at check-out then he/she is eligible for points. The OP is NOT since the boss is the authorizer and payer. So the OP is NOT eligible for points anyway.