YMMV, I just saw it in my two cards:
Get a one-time $100 statement credit by using your enrolled Card to make a single purchase of $150 or more online at att.com/smallbusiness by 10/31/2017. See terms for exclusions.
Enrollment limited. Offer valid for wireless bill pay for AT&T AutoPay and one-time payment only. In order to be eligible for the offer, you must enroll your Card and use that Card to pay your wireless bill or other service charges online directly with AT&T at att.com/smallbusiness or through the AT&T app. Purchases for equipment or prepaid, U-verse, web hosting, or wireless services that do not appear on your AT&T wireless bill are excluded from this offer. Your payments must be in the amount of $150 or more in a single transaction and completed by 10/31/17. Payments by phone, at retail locations or via third parties do not qualify. Offer is non-transferable. Must add offer to Card and use same Card to redeem. Limit 1 statement credit(s) per American Express® online account. Statement credit will appear on your billing statement within 90 days after 10/31/2017, provided that American Express receives information from the merchant about your qualifying purchase. Note that American Express may not receive information about your qualifying purchase from merchant until all items from your qualifying purchase have been provided/shipped by merchant. Statement credit may be reversed if qualifying purchase is returned/cancelled. If American Express does not receive information that identifies your transaction as qualifying for the offer, 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 may 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: CHTM:0001