Jetstar J is more of a premium Economy when compared to most Longhaul J. This is no so much of an issue with the eveing flight to Bali. However, the return to Oz is a redeye (think AA first ANC-DFW on a 757).

As JQ is NOT oneworld, as an EXP you will not have access to the new First Class Lounge in SYD before your flight to DPS- J lounge access would be available. F lounge access would be available before retuning to LAX.