This was sent to fitness first members, 10% any participating pre-paid Price Match Guarantee hotel. Obviously check hotelscombined.com and the hotels website direct to make sure its still the best price but I usually find hotels.com fairly competitive.
The discount doesn't appear to apply to taxes, example using the first hotel listing in Hong Kong below:
Thursday, July 11, 2013 A$87.57
Friday, July 12, 2013 A$87.57
Taxes and fees A$15.76
Discount
10% Discount
Terms & Conditions
Remove-A$17.51
Total
(including taxes and fees) A$173.39
The cheapest on hotelscombined.com for this hotel for the same 2 nights (Hotel De Edge Hong Kong) is AUD $193.
From the T&C's
3) Valid for ….. stay dates between 01/01/2013 and 30/09/2013.
10) Hotel bookings made using a Coupon are not eligible for Welcome Rewards credits.