soorox, I've not calculated the numbers, but if MEL and SYD were compared, wouldn't SYD still be way ahead of MEL in nonstiop flights each week to and from mainland China?
Also let's not forget the great democracy in the Republic of China (Taiwan.) 'China' in the case to which you're referring needs a 'mainland' inserted before it, noting that it is an at times brutal Marxist dictatorship where freedom of religion and movement is either not permitted or not guaranteed.
politics aside, yes SYD does have more services and cities to Mainland China than MEL
SYD: CAN, PEK, PVG, TAO, XMN, XIY, CSX, CKG, CTU, SZX, HGH, NKG, KMG, WUH, FOC
MEL: CAN, PEK, PVG, TAO, XMN, XIY, CSX, CKG, CTU, SZX, HGH, CGO
As you can see, SYD is ahead, however MEL isn't doing too bad either when considering that BNE is only connected to 3 Mainland Cities. Both MEL and SYD are the core markets for flights to Mainland China and I don't see that changing anytime soon.