[Hudson]

Technically, no.

Eligible purchases do NOT include fees or interest charges, cash advances, person-to-person payments, purchases of gift cards, purchases of traveler’s checks, purchases or reloading of prepaid cards, or purchases of other cash equivalents.

Amex receives level 3 data and sees exactly what you buy.

That being said, buying some giftcards’s mixed in with groceries is usually fine.