If you are yet unsure of the venue of vacation and the airline, then there’s no sense in choosing a co-branded credit card. If you decide to fly another, you earn just one point. There’s no versatility in co-branded credit cards. A better variant is choosing just a travel credit card and applying it to whatever the flight you’ll have. A general rewards credit card will liberate you even more, as you will earn more not only on flight, but an all purchases. The Discover it® Miles is such a card, but designed specifically for travel, so you may apply for it and start earning beforehand.