If you're a frequent business traveler, signing up for a bank credit card tied to your preferred airline is a good tactic. But which card is the best for your needs?

Here's a rundown of the best in class from each big U.S. carrier. And don't forget about the recently upgraded American Express Platinum card, the plastic coin of the business-travel realm.

Alaska Airlines

It its typically conservative way, Alaska Airlines offers the fewest cards among the traditional full-service airlines. The $75-a-year Visa Signature card from Bank of America offers 25,000 bonus miles after the first purchase and up to three miles per dollar spent on purchases. Carrying the card will also guarantee that your Alaska miles won't expire.

American Airlines

Citi's new WorldElite MasterCard is the textbook definition of a "me too" product. Its benefits package has been around for years at other carriers. Besides access to American Airlines' Admirals Clubs, expedited airport handling, a free checked bag, and Citi's waiver of its usual 3 percent foreign exchange (or forex) fee, you'll also receive 25,000 bonus miles after the first $1,000 of purchases and 10,000 elite miles after $40,000 of purchases within a calendar year. Unlike other American/Citi cards, there's no cap on mileage earnings on purchases and up to two miles per dollar on purchases. If $450 is too rich, other versions of American/Citi cards offer 60,000 bonus miles after $10,000 of purchases and no annual fee for the first year.

Delta Air Lines

Delta's symbiotic relationship with American Express means the Amex Platinum card may cover your needs if you're a regular Delta traveler. But if you're looking for more Delta-specific benefits, the $450-a-year Delta Reserve Amex card offers 10,000 Delta elite miles after your first purchase, free access to Delta airport lounges, and a free checked bag for each flight. If your only interest is earning miles, the no-fee Options card from American Express offers up to two Delta miles for each dollar charged.

JetBlue Airways

American Express handles JetBlue's credit card, and the $40 annual fee gets you 10,000 TrueBlue points after the first purchase and up to two points per dollar charged to the card. Using the card extends the life of all of your TrueBlue points for an additional year.

Southwest Airlines

The ubiquitous Chase offers the Rapid Rewards Premier Card for $99 a year. After your first purchase on the card, you'll receive credits worth about $800 worth of Southwest tickets. The card will also award 1,500 elite points for every $10,000 charged, 6,000 points each year that you carry the card, and up to two points for each dollar charged.

United Airlines

As United and Continental work to harmonize their day-to-day operations (the two carriers officially merged last year), Chase is scrambling to match and streamline its card offers. The new MileagePlus Explorer is the first card specifically designed for the merged airline. Besides a free checked bag, priority boarding, and frequent-flyer program benefits, the card's other offerings include: two airport club passes each year; 25,000 bonus miles after the first use; and a waiver of the $95 annual fee for the first year. Chase's top-of-the-line product is probably the Presidential Plus card. The $395 annual fee now covers access to about 200 United and Star Alliance airport lounges; a waiver of Chase's 3 percent forex fee; two free checked bags per flight; 1,000 elite miles for every $5,000 of charges; priority boarding and check-in privileges; up to double miles on purchases; and immediate elite status in the Hyatt Gold Passport and Avis Preferred programs. You'll also receive a $95 statement credit when you first use the card.

US Airways

The World MasterCard is the best of a mediocre collection of cards from Barclay. The modest fee ($89 a year) includes a once-a-year club pass, priority airport check-in and boarding, and up to two miles per dollar charged. You'll also receive 30,000 bonus miles if you spend $750 in the first 90 days.

To read about how American and United airlines introduced their new offerings within a day of each other, click here.

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Joe Brancatelli writes Portfolio.com’s business travel column, Seat 2B. Brancatelli is the former executive editor of Frequent Flyer magazine and operates the membership site JoeSentMe.com. You can reach him at jbrancatelli@portfolio.com.