I wonder if it would be worth adding Signature agents, too? While there is a lot of overlap with Virtuoso, there may be properties that fall under Signature's umbrella that is not covered by Signature.

To pricesquire's point, the initial list is missing some preferred agency programs. I'd also suggest adding Langham and Sofitel's programs to the list. Unfortunately, as the list grows, it may not be possible to keep with the single letter abbreviations.

B= Belmond Bellini Club
D= Dorchester Diamond Club
F= Four Seasons Preferred Partner
J= Jumeriah Passport to Luxury
L= Couture by Langham
M= Mandarin Oriental Fan Club
P= Peninsula Pen Club
R= Ritz-Carlton Stars
RF= Rocco Forte Knights
RO= Rosewood Elite
S= Starwood luxury partners
SO= Sofitel Step