ATI,
Distancia the FF program of Groupo Taca is currently running another promotion for Latin America members only, and they have been much more specific on which fares qualify for mileage, and which ones do not. I have copied what they say about fare codes for that promotion from the web site: "Award bonus is valid on applicable fares (D, B, L, W, Z, T, E booking codes are not valid)". This information is listed for a 50,000 mile bonus promotion at the Groupo Taca web site; Since D class is excluded from one promotion I would assume it is excluded from all. I bought a W class ticket from ITN for a TACA flight and found later that it was indeed excluded from acquiring mileage, and effectively unusable for the million mile run. I myself would be very leery of the D class ticket. One more important slice of information I learned from the TACA Distancia site is that only fares booked in C and Y class are valid for acquiring mileage on TACA Peru. If you are going to Cuzco of Iquitos make certain the ticket is booked in C or Y only!