I believe this is correct, provided you booked through Platinum Travel Service or your own travel agent contacted PTS. The text on the website is dated ....

The 2007 Cruise Privileges program (CPP) is only valid on voyages of 6 days or longer, and may not be combinable with group promotions depending on the cruise line. CPP may not be combined with other American Express Card offers, including American Express® Mariner Club. Blackout dates, category and fare restrictions may apply. CPP is a special benefit for U.S. Platinum Card members. Certain Platinum Cards are not eligible for certain benefits and services. The $300 ($150 per person, double occupancy) shipboard credit and $250 ($125 per person, double occupancy) Crystal Adventures shore excursion credit cannot be used in the casino or for payment of gratuities, is non-transferable, cannot be redeemed for cash or credit and cannot be combined with other shipboard credit offers. Princess upgrades applicable only within the same class of staterooms: balcony to balcony, outside to outside, inside to inside. See applicable cruise line brochure for terms, conditions and definitions that will apply to your booking. Benefits are one per stateroom. One of the travelers must be a U.S. Platinum Card member and there is a three-stateroom limit per Card member, per sailing. Payment must be made with an American Express Card in the Platinum Card member’s name. Book through Platinum Travel Service (PTS) or refer your U.S. travel agency to PTS. Bookings made directly with the cruise lines are not eligible for CPP benefits. To receive CPP benefits, travel agencies are responsible for following CPP bookings guidelines provided by Agency Services Desk (ASD): 800-443- 7672, prompt 5. Program valid for sailings completed by 12/31/08. Partners and benefits are subject to change without notice. Ships’ registries: Crystal Cruises: Bahamas; Cunard Line: Great Britain; Holland America Line: Netherlands & Bahamas; Princess Cruises: Bermuda; Regent Seven Seas Cruises: Bahamas,Wallis & Futuna; Seabourn Cruise Line: Bahamas; Silversea Cruises: Bahamas; Windstar Cruises: Bahamas.The partners and benefits described herein are accurate as of time of printing and are subject to change or cancellation without notice. American Express Travel Related Services Company, Inc. acts solely as sales agent for travel suppliers and is not liable for the acts or inactions of such suppliers. CST#1022318-10,Washington UBI# 600-469-694, ML-1192, TA-002 registered Iowa Travel Agency, NV# 2001-0126.