RedeemCouponResult should include information on any bundled "GrantedCurrencies", analogously to the GrantedItems field which is already there.
This has been previously asked in the following posts:
https://community.playfab.com/questions/5552/coupon-response-doesnt-include-currencies.html
https://community.playfab.com/questions/17544/redeemcoupon-timeout-and-grantedcurrency.html