The Amex Plat fee (USA) is $450. It is worth it the first year because you get the $200 fee credit twice (once before January 1 and once after) and a signup bonus. After the first year, it's probably only worthwhile if you use some of the other features. It is not a great card for earning points, as it is a flat 1 point per dollar. You might consider switching to the Preferred Rewards Gold, with a lower fee ($175) and 3x points on airfare, 2x on gas and groceries, and 15K bonus for spending $30K in a year. Be sure to open the PRG account before cancelling the Plat so that you don't lose your points.

I don't know about the hotels.com rewards program, but you can save serious money booking hotels on Priceline. However, if your employer is paying for your hotels, that will help them but not you.