We recently stayed at the CY Munich City Center. I booked five nights on MR points on one reservation. And on a second reservation three additional nights on an AirBerlin promotion (stay three nights, pay for only two nights).
When we arrived the front desk person had no idea what the AirBerlin promotion was or how to deal with it (the promotion required us to give our AirBerlin TopBonus number upon check-in).
I called the MR Platinum Desk back in the US regarding the confusion. They called the hotel front desk and made sure the staff knew about the promotion. On check-out the AirBerlin promotion free night was noted as such on the final bill.
It pays to have the Elite Desk talk to the local hotel staff.