account has the option to redeem both of them on one flight, but must do so across two bookings.
that's the part a bit confusing to me, it seems to suggest that I can make two reservations for the same flight using one voucher each, while at the same time saying that avios price has to be paid for another individual. Does it mean I can use the second voucher by booking a third person (paying full avios) and their companion (paying taxes "only"), separately from another reservation with my name and my companion?
Doing a quick dummy booking, when it's time to input passengers' information, my name is already pre-populated for passenger 1 and cannot be edited, so I believe the only way to utilize two vouchers for 4 passengers is to phone up the call center.