There has been discussion that Amex purchase protection benefits apply when buying through Paypal on Ebay, but my question is can an Amex offer be combined with a Paypal offer?

Specifically I have the $15 off $50 at 1800flowers in Amex Offers. I also have a $15 off $15 when using Paypal checkout. If I do Paypal checkout and fund with my Amex, will I be able to get $30 off of $65? Has anyone done this before?

Thanks!