Being close to Aussie, N.Zers have always (nearly) had both.
Vegemite is described as being a "concentrated yeast extract", while Marmite is a "yeast extract". What does that mean?

My sister is a Vegemite fan, and me, definately a Marmite person. The "nearly" related to the fact that the Marmite factory was in Christchurch and was damaged in the earthquake. This required the operation to be relocated and we were without it for about a year.
Promite and Bovril (spelling?)are similar products, but all are quite different. I was suprised to find that the British made marmite was quite different to the NZ made Marmite.
I tried to bring a jar of Marmite to Australia (and my daughter had a similar experience with peanut butter) Neither can be in your "carryon" luggage. Pack it in your main luggage if you want to keep it. Both are defined as liquid, and are confiscated.
The story with the peanut butter is that it was made in N.Z. by "Sanitarium"
(I think)
The operation was shifted to China, which generated a bit of public resistance. This led to the Australians making special Peanut butter for NZ consumption (It has no sugar in it, unlike Australian sold PNB.)
All friendly rivalry aside, it is hard to beat a bit of toast with Marmite or Vegemite (if that is your preference) with your cuppa in the morning.
Mike I am pleased for you that you have your Vegemite available to you.
I can just see Keith Webb doing a victory roll in support.