Just have to clarify something
JQ cabin crew do not share hotel rooms whether they are Aus based or SIN/BKK/HKT based. On a side note Jetstar Pacific cabin crew do share hotel rooms when the gender numbers are even.
JQ cabin crew in Bali either stay at the Holiday Inn or Holiday Inn Express subject to occupancy levels. Anecdotally the cabin crew prefer the express as it is newer and cleaner. JQ pilots stay at the Inn. Along with Virgin crew and the occasional Qantas crew.
As for Bali not supporting premium airlines, I beg to differ given a Qantas A330 from SYD, a 737 from MEL, multiple Virgin 737s and the business (premium economy) cabins on four daily JQ 787s being mostly full on a daily basis.
Cheers