3 months Apple TV

I bought a couple of days before a new MacBook Air and I'm supposed to get a free 3 months membership for apple tv but I cannot redeem it. I already got a free 3 months membership when I bought an iPhone. Is it possible to be able to claim it only the first time you are buying a product or every time you buy a new apple product under the same Apple ID, you can claim a new 3 months free membership?