Any Chase card that is part of their Ultimate Rewards program earns 2% (cash) on all airfare booked through their website. I don't think the cards you mentioned are part of Ultimate Rewards, since they give miles, but the Chase Freedom and Sapphire cards both are. In my experience the website is an okay booking engine - it seems to use Expedia as the backend, so anything that you can find on Expedia is bookable there.