Between May 1 and September 9, 2018, earn double base Hilton Honors points on paid Hilton stays, excluding Hampton by Hilton Hotels in Mainland China. Register for the promotion here by September 9.
The last Marriott Rewards promotion ended July 20, 2018, and the first promotion in the new Marriott Rewards program hasn't been announced yet.
World of Hyatt
Between September 1 and November 30, 2018, earn bonus points based on the total number of eligible nights stayed, starting at 5 eligible nights, including free night awards but excluding Oasis homes and Small Luxury Hotels of the World properties. Register for the promotion here by October 15, 2018.
IHG Rewards Club
Here's the list of current IHG PointsBreaks properties, for reservations made through September 30, 2018.
The last Radisson Rewards promotion ended August 31, 2018, and the next promotion hasn't been announced yet.