Nice find...

It looks to me the killer is in the details, not a bonus of 20,000 points but earn up to 20,000 points.
From the terms and conditions.
Bonus Frequent Flyer Points
New Zealand and South America - 1000 (New Zealand) or 2000 (South America) Qantas Frequent Flyer Points will be awarded as advertised provided on the following: 1. Per person a minimum of return Qantas airfares to New Zealand or South America, 7 days car hire (NZ only), 7 nights accommodation and a 3 day lift pass.
USA, Canada, Europe, Japan - 2000 Qantas Frequent Flyer Points will only be awarded per adult travelling on a SKIMAX Package consisting of a Qantas Airfare, 7 nights accommodation and a 6 day lift pass (except Europe).
Unless they have left off a '0' in the terms..