Have had my Amex linked to PayPal account for years, and yes, far as one has seen all benefits and coverage apply long as one has met terms otherwise.

IIRC Amex only looks at how payment was made; that is were charges billed to and paid for on American Express card. Far as Amex is concerned PayPal just processes the transaction. https://www.quora.com/If-I-pay-with-...rranty-expires

Upon examining my Amex statements each month things paid for via PayPal rack up same points as anything else.

However as one stated you have to do some research as things vary by what one has purchased and where. If you're buying merchandise off eBay for instance: https://www.quora.com/Does-American-...bought-on-eBay

For the record your query has been made before: Amex & PayPal payment question

In many ways: https://www.google.com/search?q=amex...ih=561&dpr=1.5

Amex and PayPal recently snuggled closer in bed with each other, which depending upon your point of view is either a good or bad thing. https://www.doctorofcredit.com/ameri...ases-and-more/

Only issue that *might* occur is if using Amex via PayPal to pay for a category specific benefit, but retailer/seller doesn't come up under that category.

Something like a promotion for spending $1000 in a certain time on travel and entertainment. You find a nice restaurant and blow $500 on a meal, but they don't take Amex, however PayPal is fine. So you run the bill through PP charging your Amex card. When bill hits your account it isn't credited as "entertainment" because the restaurant has set up it PP account under something else or whatever. Usually it only takes reaching out to Amex CS to get that sort of thing sorted.