Until Citi adds American Airlines as a ThankYou transfer partner, Citi ThankYou will always be the least valuable of the major
transferrable points currencies.
The good news is that Singapore partners will
all transferrable points currencies — including Amex Membership Rewards, Chase Ultimate Rewards, Citi ThankYou and Starwood Preferred Guest — so it's still entirely possible to book these seats.
However, transfers from
some transferrable points currencies are instant, so you can make sure there's availability for your trip before you transfer your miles.
Notably, it's the only
transferrable points currency that offers the ability to transfer to American Airlines.
Not exact matches
Amex Membership Rewards are arguably the best rewards
currency out of any
transferrable points program, including Chase Ultimate Rewards.
EVA Air is one of Taiwan's more widely known airlines, they are a Star Alliance member, which meant I could redeem some Ultimate Rewards
points via United, or Membership Rewards
points via Aeroplan, or nearly any
transferrable currency via Singapore KrisFlyer.
The most valuable
points, at the top of my
currency list, are
transferrable points.