IOTL Newfoundland joined Canada in 1949 many years after Canada had already become a Dominion. What POD would be needed for New Zealand to join Australia about the time IOTL, New Zealand became a Dominic?
in 1949? Way, way too late.
IOTL, Newfoundland did join Canada in 1949, 82 years after Canada became a Dominion.
IOTL Newfoundland joined Canada in 1949 many years after Canada had already become a Dominion. What POD would be needed for New Zealand to join Australia about the time IOTL, New Zealand became a Dominic?
When it comes to the Newfoundland, remember that it taking that long to join Canada was a bit of a fluke. Talks were being finalized in the 1890s for Newfoundland and Labrador to join Canada, but the sudden death of Canadian Prime Minister John Thompson postponed things indefinitely, since his successor, Mackenzie Bowell, was engrossed by the Manitoba School Question and other domestic problems.
If Newfoundland joins Canada in the 1890s, that's a similarly realistic period for Australia and New Zealand to join up, I think.