When you log on to the hhonors site there is a scrolling message box on the upper right. One of the messages for me was this:
Your Hilton HHonors Platinum Credit Card from American Express has been upgraded! New benefits, new ways to earn even more HHonors bonus points, all still for no annual fee.
Click here to learn more about what we've added to your Card.
The link takes you to:
http://www.hiltonhhonors.com/process...px?lp=amexcard
Don't beat yourself up for not seeing it before. It was just announced on 4/15 and you have to click on the ambiguous message above to see the promotion.