Showed up on multiple cards including AU. YMMV with Amex offers. Seems like Home Improvement for Spring/Summer offer. Might work on GC as well. Not sure if multiple transactions of 100+ would work but looks like it should from below T&C.

Enrollment is limited. An “eligible purchase” means a purchase of $ 100 or more made in a single transaction by 8/31/16, on up to $ 2,000 in total purchases, excluding HD Direct, Home Decorators Collection, Home Depot Foundation, Home Depot Fuel, Home Depot Car Wash, Home Depot at-home services, Home Depot Carpet Clean, Your Other Warehouse, Red Beacon brand, and third party installation services purchased in home. Offer valid for in-store purchases only. Valid at any participating location in the US and US Territories. Offer is limited to a total of $ 100 in statement credits per American Express® online account. Must add offer to/enroll Card and use same Card to make the eligible purchases. Offer is non-transferable. If you order an item during the offer period but it is not sent/provided to you until after 8/31/16, it may not qualify for the offer. Statement credit will appear on your billing statement within 90 days after 8/31/16. Statement credit may be reversed if eligible purchase is returned/cancelled. Note that American Express may not receive information about your eligible purchase from merchant until all items from your eligible purchase have been provided/shipped by merchant. If American Express does not receive information that identifies your transaction as an eligible purchase, or if there is a delay in merchants submitting transactions to us, you will not receive the statement credit. For example, your transaction will not qualify if it is not made directly with the merchant. In addition, in most cases, you will not receive the statement credit if your transaction is made with an electronic wallet or through a third party or if the merchant uses a mobile or wireless card reader to process it. By adding an offer to a Card, you agree that American Express may send you communications about the offer. POID: BZFX:0003