I retired from teaching 11 years ago and as FannyCornforth has said, learning about other faiths and cultures was and I'm guessing, still is, part of the National Curriculum in the UK.
I taught in a Catholic primary school and in KS1 the focus was on other branches of Christianity. In KS2 it was learning about other faiths, Islam, Judaism, Sikhism and Hinduism. Children visited other places of worship, if possible and met other faith leaders.
Our school had quite a diverse ethnic mix so there was informal sharing of knowledge about customs and festivals which was supported in other areas of the Curriculum where possible.
I understand you live in Australia, nanna8. I'm not sure what the position is on learning about other religions and cultures is over there but I would be surprised if there were not some provision for it there too.