This belongs to the good to know department. When a property issues you a bonus due to booking a special rate or for the compensation, they pay for the Marriott Rewards for the points issuance.
A LoyaltyLobby reader forwarded me a copy of the PDF that one Marriott affiliated hotel had sent him:
Marriott charges $65 for every 10,000 points that the property issued to your account. You can buy Marriott Rewards points directly up to 50,000 per calendar year for $125 per 10,000 points. You can access Marriott Rewards web page for buying points here.
It is always good to know the amount that the property must pay for the Marriott for the issuance of the bonus / compensation points. I would certainly buy points (a lot) if Marriott would sell them to me at the same rate.