[2] Although Peni was born in New Zealand, with a short period in the Chatham Islands, he moved to Perth, Western Australia at a young age, playing rugby for Wests Subiaco and playing for Willagee Bears in the Western Australian Rugby League.

On 17 October 2015, Peni represented the Cook Islands in their World Cup qualifier match against the Tonga, playing at centre in the 28–8 loss at Campbelltown Stadium.

A pass from Jono Lance after a line out, followed by an explosive run, which lead Peni to a quick try one minute into the game against the Reds.

[10][11] In June 2017, Peni re-signed for the Force for another two years,[12][13] with the ARU vowing to honour player contracts despite the team being axed from the competition.

[16][17][18][19][20] Peni scored his first try for the Brumbies in round four of the 2018 season against the Rebels in a 33–10 defeat at AAMI Park, Melbourne.