I’m not sure when it changed - but twitter search indexing of URLs definitely did change at some point… i’d blame that over relevance filtering.
You need to use "url:abc url:net.au" to search for any links that have abc.net.au
"news.com.au" works like you said, but i’d still use "url:news.com.au" instead.
"der-postillon.com" fails because of the - i assume: the dash is a special search operator.
Use "url:der url:postillon.com" instead.
I’m guessing it’s because of the way twitter tokenizes and indexes tweet text and url text. Don’t think there’s documentation on exactly how tokenization is handled for search & streaming. But if there is, i’d love to see it.
Unfortunately it’s trial and error to get it to work for these edge cases.