Joining the fast moving trend of platinumizing airline co-branded credit cards is Bank of America’s ‘Alaska Airlines VISA’ program. Cardholders of the new ‘Alaska Airlines VISA Platinum’ card will receive 5,000 bonus miles after opening an account, 1,000 bonus miles each year after renewal and double miles for each Alaska Airlines/Horizon Air ticket or vacation purchase. Each year, cardholders will also receive one $50 round-trip companion certificate and two one-way First Class upgrade certificates. There is no limit on mileage earned and mileage does not expire. Other benefits include one mile per regular purchase dollar and four Alaska Airlines ‘Board Room’ passes. Alaska Airlines is the 10th largest U.S. carrier and serves more than 40 cities in Alaska, Mexico, Canada and five Western states. Two weeks ago America West’s co-branded credit card went platinum. American Express and Delta Airlines took their ‘SkyMiles’ credit card platinum in June. US Airways went platinum one year ago while American Airlines and United Airlines launched platinum versions of their credit card programs in early 1998, according to CardTrak ([www.cardtrak.com]).