I suspect these were either imported by G. Herring Pty. Ltd., or made here by the company. G.Herring was importing buttons from around 1936-7, and selling them on G. Herring branded cards. From 1939, if not before, they were making plastic buttons in Sydney.
As G.Herring was importing and/or making casein buttons from around 1937, but did not use the brand Beutron until 1946, it was likely that some other brand name(s) were used. I only have two other partial Bonnie Buttons cards; one has buttons identical to an example of British Made “Beutron Wash buttons”. The ability of buttons to stand up to boiling was a big advertising feature in the 1940-50s.
“Tub buttons” were advertised from 1947-1950.