I’m new to this game and although I have taken advantage of many of the offers currently out there I am wondering what to do for my fiance’s position.

She just got a consultant type job where she will be traveling to more rural towns (in Texas, Oklahoma, and New Mexico), some by flights, some by flights then renting car, some by car alone, and she is suppose to get one card to put her business expenses on. I’m not exactly sure the best way for me to direct her as far as maximizing rewards out of the deal. My initial thought was have her sign up for the 75k AAdvantage card to get those miles by spending and just have her sign up for the points programs along the way depending on where she is able to stay or car rental company. Problem with that is we fly out of IAH, so therefore most of her flights will be Continental most likely. I love the SPG card, but there will be no SPG properties anywhere she travels unlike I who only travel to major metro areas. What would you all do for a card to maximize points that are easily transferrable? Thanks.