Hi,
Not sure whether this is what you are looking for? Below is what I received from MR Customer Care regarding the procedure to MegaBonus Free Cert redemption. Hope it helps.


Once you have signed into your Marriott Rewards account on MarriottRewards.com, you will be able to see the certificates listed in the "Upcoming Reservations" page or the "Marriott Rewards Activity" page.

For your convenience, we have included instructions below that can guide you through the process of redeeming your rewards.

1. Start at the Marriott.com homepage (http://www.marriott.com), and click on "My Account" located in the upper right-hand side of the page to sign in to your Marriott Rewards account.

2. Enter your destination in the "Find: Hotel" section in the center of the page. Do not enter the dates of your stay at this point. Also, be sure to click on the box marked "Use Marriott Rewards points." Click on the red "Find" button to continue.

3. A list of hotels in the area will be presented as well as the Marriott Rewards category of each hotel. Click on the red "Select" button next to the hotel of your choice. To redeem the certificate without using additional Marriott Rewards points, select a hotel that is listed within the category range on your reward.

4. You will now be able to enter the dates of your stay and select a room. A list of available rooms, as well as the points normally required for your stay will be displayed. Click on the button next to one of these options. You can then confirm your room preferences. Click on the "Continue" button.

5. Review your personal information in the fields provided. After the contact information section of this page, you will see options to either "Attach the e-Certificate(s) below to my reservation" or "Order new e-certificate(s) and automatically deduct the points from my account." If you intend to use your promotional certificate, use the first option listed here. Click on the "Continue" button at the bottom of the page.

6. The final page will provide your confirmation number. You may wish to print this page for future reference.

If you need additional assistance, please feel free to reply to this email of contact an Internet Customer Care Associate by phone at 800-721-7033 (toll-free in the United States and Canada). We are available to help you 24 hours per day, 7 days a week.

For our international guests, a listing of informational reservation offices is available at the following site:

http://www.marriott.com/reservation/worldnum.mi

If we can be of further assistance, we invite you to reply to this email.

Thank you for choosing Marriott.