Intercasino may have a good name but TLC who organised the promotion certainly do not. Try googling TLC with "free flights" and words like scam and fraud.
It is quite possible they never understood the cost of flights from australia to the USA. It is hard to get a fare to the USA from Australia for under $2,000. routing restictions on the ticket mean it would probably cost them much more.
whatever the reason is they seem quite determined to make sure australians cannot collect
check the relevant post on the australian poker forum
http://www.pokernetwork.com/Nnoticeb...mmary_ID=16554