Unfortunately,
Celestial Seasonings doesn't yet ship overseas, but here's the contact info for their Australian distributor, who would be happy to tell you where to find some in your area (assuming you live in
that Sydney):
Australia
United Foods Pty. Ltd.
Unit 1
39-41 Allingham St.
Condell Park
New South Wales 2200
61 2 9790 0866
61 2 9793 8046 (fax)
(I trust that makes sense to you. Sure doesn't to me. 
)
They're Boulder-based, so they have a wide range of non-caffeine beverages without strange additives.