Just last week, I visited one of the Regus locations in Bangkok and wrote a piece about it that you can access here. Regus offers temporarily office space in 95 countries and has more than 1500 locations. I have received Regus Businessworld Gold offer few times for being an elite member with airline frequent flier program, but that is not a requirement to get this access for free, however.
I just used Google and searched the airlines that offer complimentary Businessworld Gold membership for their frequent fliers. You can get 6 months free membership via Enrich (not even required to join the program) and 12 months free via Lufthansa’s Miles & More (need membership number).