As to the "honeymoon theory", I think that was highly unlikely, they were not wealthy people at all.
However, there is a record of Joseph Taylor Hind's nephew, Henry(Harry) Kenyon Hind (b 1866), his wife Elizabeth and 2 daughter, Constance & Doris, travelling to NZ on board the "Gothic" from England in 1901, but they too were back in England at the time of the 1911 Census.
Maybe this was the one time my grandmother got confused when writing up her story, and mistakenly confused that journey, but I find it highly unlikely, as their trip took place some 20 years after her father's journey that she referred to.