Hi Chris,
You have 2 issues here:
1. It doesn't make sense to put the us version on http://www.camilla.com.au/us/ - .com.au is an Australian domain extension and therefore geo targeted by default to Australia. If you want to have a us version you'll have to put it on a generic domain extension (.com / .net / .org / etc geo targeted in search console to the us) or use the .us extension
2. Hreflang is on page level - not on domain level - on all pages of your site you put the hreflang pointing to the "us homepage". What you should do is for each page on your site (both us & au version) you will have to put at least two hreflang tags:
Example http://www.camilla.com.au/collection/my-wandering-heart-resort-15 & http://www.camilla.com.au/us/collection/my-wandering-heart-resort-15
On both pages put:
<link rel="alternate" href="http: www.camilla.com.au="" collection="" my-wandering-heart-resort-15" hreflang="en-au"></link rel="alternate" href="http:>
If you want to have one version as default - then also add
(if it's the us version you want as default - check http://googlewebmastercentral.blogspot.be/2013/04/x-default-hreflang-for-international-pages.html)
The message "reciprocal not found" indicates that you only put the hreflang to the us version - and that on the us version there is no hreflang link to the au version.
You can scan all the content on Moz on hreflang - but useful links are:
https://moz.com/blog/hreflang-behaviour-insights http://www.aleydasolis.com/en/international-seo-tools/hreflang-tags-generator/ https://support.google.com/webmasters/answer/189077?hl=en
Dirk