While it's not a definitive list of all the combination and programs (I'm not convinced such a thing exists), MillionMileSecrets has a pretty decent list of Hotel Loyalty Programs:
1) Choice Privileges - includes Ascend Collection, Cambria Suites,
Clarion, Comfort Inn, Comfort Suites, EconoLodge, MainStay Suites,
Quality Inn, Rodeway Inn, Sleep Inn, and Suburban brand hotels.
2) Club Carlson – includes Country Inns and Suites, Radisson,
Radisson Blu, Park Inn by Radisson, and Park Plaza
3) Hyatt Gold Passport - includes Andaz, Grand Hyatt, Hyatt, Hyatt
Place, Hyatt Regency, Hyatt Resorts, Hyatt Summerfield Suites, and
Park Hyatt brand hotels.
3) Hilton HHonors - includes DoubleTree, Conrad, Embassy Suites,
Hampton Inn, Hilton, Hilton Garden Inn, Home2Suites, Homewood Suites,
and Waldorf Astoria brand hotels.
4) Marriott Rewards - includes Marriott Hotels & Resorts, JW Marriott
Hotels & Resorts, Renaissance Hotels, Courtyard by Marriott, AC Hotels
by Marriott, Residence Inn by Marriott, Fairfield Inn & Suites by
Marriott, TownePlace Suites by Marriott, SpringHill Suites by
Marriott, The Ritz-Carlton Hotel Company L.L.C., ExecuStay, and
Marriott Executive Apartments Grand Residences by Marriott brands.
5) IHG Rewards - includes Candlewood Suites, Crowne Plaza, Holiday
Inn, Holiday Inn Express, Hotel Indigo, Intercontinental Hotels &
Resorts, and Staybridge Suites brand hotels.
6) Starwood Preferred Guest - includes Aloft, Element, Four Points,
Le Meredien, Sheraton, St Regis, The Luxury Collection, Westin and W
7) Wyndham Hotel Rewards – includes Baymont Inn, Days Inn, Hawthorne
Suites, Howard Johnson, Knights Inn, Microtel, Ramada, Super 8,
Travelodge, Wingate, Wyndham Hotels & Resorts, Wyndham Garden, and
Wyndham Grand Collection.
if we can find a more definitive list that's great, but after a while of searching this is the best I've found, even though there are already obvious gaps.