The Australian Bureau of Statistics (ABS) in a press release did not state you shouldn't declare your religion as Jedi. Rather it said you should not falsify your religion. In their words:
ABS recognises that people have a wide range of belief systems.

If your belief system is "Jedi" then answer as such on the census form. But if you would normally answer Anglican or Jewish or Buddhist or something else to the question "what is your religion?" and for the census you answer "Jedi" then this may impact on social services provision if enough people do the same.

ref: http://www.abs.gov.au, then do an internal search on 'jedi'

So if Anakin Skywalker was residing at 123 Camberwell Drive Rooty Hill Sydney on Census night he would be within his rights - nay, obliged - to declare his Jedism. Enough Jedi Knights in the Western suburbs would strengthen the case for a government-funded Jedi school, no doubt. After all, Jedis pay tax too.

I wonder if the census would disaggregate Jedi down to which side of the force an adherent would belong to; like within the major religions the Jedi had their own schism too, and we record separately Catholics within Christianity, Sunnis within Islam etc.

Yes, but Anakin Skywalker was fictitious. Yet there are enough real people in Australia who put more trust in the beliefs, world view and legends of popular culture than in established religions to perhaps think we should be readdressing the relative importance of this question on the census. Religion might have been important fifty years ago, but its influence has waned as television and other media take hold of public imagination about what higher forces exist beyond the material world.

Interestingly, the ABS has not applied a stricter test used by other government agencies to elicit the veracity of personal information, that of what other people think. Centrelink for example would ask Do other people think you two are in a relationship ? in assessing if a male and single mother living together are actually in a de facto relationship, which could affect the elegibility criteria for a Parenting Payment (Single) Allowance. Certain religions like Juadism are exclusivist, and I doubt few people would consider I am Jewish if they see how I devour pork yum cha. Likewise people could doubt your Jedi religion if you have never attended the requisite training, and the ABS could start slapping $1000 fines on these pretenders if, for example, they fail to make a rock levitate when demonstrating a Jedi mind trick.

The crux of the press release was to reinforce the importance of the census, requesting that people's civic mindedness would motivate people to declare personal details truthfully and accurately. One could counter that religion does not deserve the attention (and funding) in our society, and that popular culture deserves more attention. Why not fund Klingon language schools over Latin ? Or recognise a Hobbit marriage just as you would a Wahabist one?