Destination with Multiple Airlines using Points
 

If I am flying to a destination that requires multiple airlines on points reward ticket are the points required calculated for each airlines sector or just as if it was all on the one airline?

You don't say which airline program. They all have different rules.
On the LH program you can mix from a list of airlines as long as you stay within the limits (number of coupons/flights, stops etc).
A Germany-US for example could be HAM-LHR on LH, then LHR-LAX on NZ and LAX-SFO on UA.

Most airlines are usually same/less points on their own metal, but , for example, AC
charges more for flights to Europe entirely on their own metal than they do for rewards on other airlines, or on mixed rewards.

Thanks for the replys sorry forgot to mention that I was refering to Sinapore Airlines any further help would be appreciated