>Maybe. I found a Delta-Continental CC. But I am hoping to find one that is affiliated with all major airlines.

Amex rewards are affiliated with Continental, and continental is affiliated with Delta and others.

Amex rewards are useable as either continental miles or a number of other things. You just go online, transfer miles from amex to continental and then call continental and get the tickets from them. You will need to have a frequent flier account with continental to transfer miles to.

If you want American Airlines, Citibank has the AAdvantage cards, but they have limits to how many miles you can earn through purchases per year.

You will not find a card affiliated with ALL major airlines. If you do, you're likely to find MAJOR restrictions on how to use your miles.

Keep in mind that if you expect to be able to travel using your miles (with any airline), your schedule has to be VERY flexible or be able to plan WAY in advance, as there is a very limited number of "miles" seat in every airplane regardless of the airline.