This program is only as good as the servers who have to give you your credit. You MUST request that they bring the device for logging in to your table and enter the information yourself.
This is the ONLY way you will get your credits reliably. On a busy night in a restaurant, servers don't want to bother with this step, and promise to put the information in for you. It won't happen.
You can go through the process of claiming your receipt on-line, but who wants the hassle. You might want to just skip this promo, and only visit their restaurants when you think it's worth it without the bonus.