American Express still has the 10+10 membership rewards point promotion for the Platinum Charge Card (up to 16.000 SGD) and the Platinum Reserve Card (up to 4.000 SGD):
For every SGD spent with Platinum Partners, one earns 7.8 KF miles!
http://www.10timesmembershiprewards.com.sg/earn-points
Depending on how much you value one KF mile - the discount is pretty substantial:
16.000 SGD spending on the Charge Card gets you 124.800 KF miles. A saver return in First Class SIN-FRA is 140.250 KF miles.