Originally Posted by
xliioper
Basic Economy flights (including Basic Economy Award flights) qualify for DL Amex first bag free benefit, they just need to be Delta operated and Delta marketed flights (I don't believe there are any Basic Economy awards on partner flights yet, so I presume this trip meets the requirement). There are longer haul international routes where a main cabin fare will already get you a free bag (like US - Asia/South America/Europe). The DL Amex card will not provide an additional free bag in these cases as it is a first bag free benefit only and does not stack on top of existing allowances.
However with main cabin bookings, the 2nd bag will charged discounted rate. Ie SAT-SCL in main cabin you get bag 1 free and 2nd bag for $60 instead of $100. (Basically they take $40 off the cost of 2nd bag since 1 bag is already included with main cabin fare) If you booked BE the 1st bag is free because you have the AMEX, thus bag 2 is $100.