If you were flying MEL/SYD-(QF)-ADL and ADL-(SQ)-SIN on separate tickets then Qantas policy is not to interline bags.¹
It really depends on SQ's policy when you check-in in Europe.
¹ QF will for connecting oneworld flights on separate tickets.
Last edited by serfty; Oct 23, 2011 at 4:01 pm
Reason: as posted by Tyrolean