The Republic of Wynnum incorporates the suburbs formerly known as Wynnum and Wynnum West. These suburbs combined have a population of around 29,500 (2017). The neighbouring suburbs of Lytton and Port of Brisbane share the 4178 Australian postcode with Wynnum and Wynnum West, but are not currently included in the new nation, although they are welcome to apply.
If the Port of Brisbane does apply at any point, the name will change to the Port of Wynnum. Two islands in Moreton Bay, St Helena Island and Green Island are also welcome to apply to become a part of the new country, as well as Lamb Island, which considered seceding in 2013.
More information on the Republic can be found here…
https://www.wynnumcentral.com.au/
https://brisbanebusinessbayside.au/
http://en.wikipedia.org/wiki/Wynnum,_Queensland