It really depends on the merchant, but it might be worth a try. You might as well get something for the miles vs just paying to transfer or buy miles. Have you signed up for the FFF promo yet? If so, you should be able to see your points if you go to 'Worldperks', 'Manage My Account', and then 'Points Summary'. If you haven't signed up for it yet, your past qual activities will not count. See T&C.