This collection of caches has nothing to do with the Church Micro series in the UK. Given that the Australian 2016 census indicates that No Religion and Jedi Knight are the fastest increasing classifications of the optional religion question "What is the person's religion?" it is not surprising that there is surfeit of empty churches that have been repurposed.
Some history
Few details are known about the St John's Anglican Church (formerly St John's Church of England). A Local History brochure states 'Originally built as the Primitive Methodist Chapel, later used during 1884-1889 by the Salvation Army. Purchased by the Anglican Church in 1890 (the congregation had outgrown the original building), after which the porch was added to the building.
Now to find GZ
Number of iron crosses = 1 then use S33 09.452 E138 54.660
Number of iron crosses = 2 then use S33 09.311 E138 54.715
Number of iron crosses = 3 then use S33 09.179 E138 54.795
happy hunting!