If it actually says on the page "congratulations on redeeming your reward", and it's from mycokerewards website, then that's the site that you have to "spend" your points from coke products to get coupons/prizes/etc.
Exactly!! Someone redeemed their coke points for it and then posted the link for the entire world. I wouldn't be surprised if it wasn't accepted anywhere and rightly so.
This kind of things is why so many stores will no longer accept internet coupons.