When I go to book I am seeing two options for my international flight plan, one is the Basic Economy at 21,000 miles and the other, for an added 6,000 miles, is Main Cabin. The benefit of Main cabin being selection of seats, refunds if cancelled and included bag.

I am a holder of the AMEX Delta Gold card ($99/yr card):

1) is the free bag perk available for international flights? (the AA Barclays card free bag is only for national flights, which is why i ask)
2) ignoring the seat selection and refund aspect of Main Cabin and looking only at the included bag, if I book with miles will the AMEX card allow me to get a free checked bag for everyone in my party (wife and i)? Or does the ticket need to be booked as $ not Miles to get this perk?