The following link explains how to get the voucher:
http://www.wotif.com/info/flights/wotifvoucher?intcmp=IMP1
This link to the terms and conditions of the voucher:
https://securepayment.wotif.com/info/GiftVoucherTermsAndCond…
Basically I could not find an end date to the deal and the use by date for the voucher seems only to be available upon booking confirmation.
I could not enter a one way fare to Australia from overseas. You can do one way from Australia.
A Bali airfare comparison between the Jetstar site and wotif yielded exactly the same fare, thereby avoiding the Jetstar visacard service fee of $8.50 as it was included in the wotif quote.
Wotif levy a $16.95 booking fee hence:
Voucher@ $20-$16.95 booking fee leaves you $$3.05 in advance.
$3.05 plus no J* card fee of $8.50 = an overall saving of $11.55 off a hotel stay
Of course do a hotel comparison using wego.com and hotelscombined.com to ensure wotif are reasonable.
So if wotif is your thing good luck.
$16.95 booking fee - goodness!
I use POLI so no cc fee.
I did a dummy search for a MEL-HBT and its $99 on jetstar
But $108 on Wotif (although the qantas one was identical fare)
I would say check closely with this one.
Interestingly though the luggage was slightly cheaper through wotif for jetstar than the site itself