http://www.flyertalk.com/forum/Forum63/HTML/001056.html
<font face="Verdana, Arial, Helvetica, sans-serif" size="2">Point accrual is limited to individual travel and the room must be paid for individually by the member. If the member attends a convention or group meeting and individually pays Marriott directly for the room, he/she will be eligible to receive points for the stay. However, contract rooms, rooms reserved by corporations on an ongoing basis, master-billed rooms and rooms booked at the Marriott associate rate or friends and family rate are not eligible to earn points.</font>
In other words, you're not entitled to points for your room rate.