On the follow up of the investigation regarding the Australia Visa waiver bilateral agreements in Schengen space, below is the reply we received from the Sweden Embassy in Canberra.
The Sweden embassy was one of the embassies that gave us the clearest answer regarding our query on the bilateral agreements, providing even further clarification regarding what could happen when visiting the other Schengen countries that may not have similar agreements.
Extract from email received from the Sweden embassy in Canberra dated 31 October 2018:
"Sweden and Australia have a bilateral visa wavier agreement with which allows Australian citizens to enter into Sweden for an additional 3 months once the 90 visa free days have been used. The agreement states that you can only claim the bilateral 3 months if you have not spent all the visa free 90 Schengen days in Sweden (or Denmark and Norway), all visa free days used in Sweden (Norway or Denmark) must be deducted from the 90 bilateral days. You might be asked to prove that you have used your 90 visa free days in other Nordic countries when you enter into Sweden so it is of importance that you either have your passport stamped or save prof of travel. Any visa free days spent in any Nordic countries will also be deducted from the total bilateral days in Sweden"
***ANYONE that wishes to use this information to plan their travels within Schengen space is at their own risk and should seek further confirmation from the embassy of the relevant countries and their border police for further details on these agreements, we are just sharing some of our findings and will not accept any responsibilities for the information stated in this post and related posts. This information was received by email from the listed countries embassies in Canberra when queried about the agreements, their replies are copied to post of each listed country on the lists above, for reference only.
*** If you have experience using the different Australia Visa waiver bilateral agreements in Schengen space give us a shout and help us improve this post contents so that other travellers may more easily plan their journeys.