Hi Uli,
welcome 2 Shangri-La hotels: a really excellent hotel group 4 frequent travellers.
Circle programme is 4 getting hotel benefits. You can't collect points, but U can collect airline miles. That means U earn stay/night credit with Circle for tier qualification and airline miles 2 your frequent flyer programme: as U are a KLM Flying Dutchman member, U may earn airline miles with them (or with LH / AA).
Shangri-La comped my Starwood Platinum 2 Shangri-La 'Elite' (= name of Top Tier. Quite confusing tier names) in April 2004. Comp is valid until 2006. I received a referral from a friend who has top tier with Shangri-La (I often stay in HKG and SIN. I sent Shangri-La a proof of Starwood Platinum and my stays in HKG and SIN + friend's Shangri-La 'Elite' referral). A collegue was able 2 get a comp from Marriott Platinum this year, too.
Hope that helps.