A URL reference would be nice. A quick Google Search seems to say that you only get the 10 bonus nights if you have booked a minimum of 10 rooms.
"No, You will not earn Marriott Rewards points or miles for any rooms you book for your meeting or event at Residence Inn by Marriott, TownePlace Suites and Marriott Executive Apartments."
Look for "Rewarding Events"; there are two types of meetings, and the other type only gets nights credit for enough nights (but also provides points credit).