But seemingly out of the blue, he has switched allegiance and will wear an Australian jersey at Eden Park.
New Zealand cannot complain too much about this. From the fast-tracking of Nathan Fien onwards, it has gone out of its way to entice players with strong Australian connections to the Kiwi ranks. Tonight, Mackay-born fullback Josh Hoffman will be in New Zealand colours.
But the tit-for-tat acquisition of Tamou carries a new and ominous warning to New Zealand. His decision appears to have been motivated more by the prospect of earning an extra $50,000 a year playing for New South Wales in State of Origin games than representing Australia. It would be idle to think others of the increasing number of young New Zealanders playing across the Tasman won't succumb to the same financial temptation if the decision is left in their hands.
Most sports have taken that decision away from individuals by imposing representation criteria. It may be a reflection of the relatively low status of the international game that this has not yet happened in rugby league. But the Australian Rugby League Commission is confronting the issue in terms of State of Origin eligibility after several controversies, perhaps the most notable of which involved New South Wales-born and raised Greg Inglis playing for Queensland.
The commission has eschewed simplistic responses, such as relying on only the place of birth. Instead, state eligibility will be decided by a majority of five categories - where a player was born, where he played most years from under-6 to under-18s, where he spent most years at school, where he played his first state-run junior representative competition above under-15s, and for whom he played his first school state representative match.
A variation on this theme appeals as the basis for international eligibility. It would put an end to the sort of pressure that is now being applied to young men. In the case of Tamou, whose mother insists he will always regard himself as a New Zealander, this led to much plaintive agonising. It would also remedy a situation that is likely to work increasingly against New Zealand.
Not only in rugby league are sportsmen and women with dual eligibility seeing greener pastures overseas when they are left to make the decision for themselves. Sacha Jones, once New Zealand's second-ranked women's tennis player, has switched to Australia in search of better coaching and financial reward. And this week Cecilia Cho, once the world's No 1-ranked amateur woman golfer, opted to play professionally as a Korean.
The 17-year-old moved from Korea to New Zealand when she was 8. Both cases further highlighted the potential pitfalls in pouring money into young players in sports that have non-existent or pliant eligibility rules.
Clear criteria would remedy a festering problem in rugby league. The lack of these is a blot on a sport that has been a trail-blazer in many other respects. In the end, the game's credibility, as much as the strength of the Kiwis, is at stake.
