Pomeroy was born in Penrith, New South Wales.

Pomeroy made his first Premiership debut with the Panthers in Round 21, of the 2004 NRL season. After only sporadic NRL appearances for the Panthers, Pomeroy signed with the Cronulla-Sutherland Sharks in 2006. A serious groin injury that year limited his appearances on the field for Cronulla to eight games. In 2007, he became a regular at centre in the run-on side and scored his first hat-trick of tries in Round 6. Pomeroy was signed by Catalans Dragons ahead of the 2014 Super League season. In 2015, he was sent off in two consecutive home games against St. Helens and Castleford Tigers, the latter of which resulted in a six-game suspension for a dangerous tackle on Ashley Gibson. Pomeroy was one of seventeen Cronulla Sharks players found guilty of using illegal substances under the club's 2011 supplements program, having a twelve-month suspension (which had already expired due to backdating) recorded against his name.

Pomeroy was selected on the bench for City Origin in 2007 and was also named in the City side in 2008. Later this same year, his successful season was rewarded with selection in the Prime Minister's XIII side to play the Papua New Guinea Kumuls.

Pomeroy was charged with assault occasioning actual bodily harm after allegedly punching a fellow concert-goer in the face during a performance by American rock band Korn at the Sydney Entertainment Centre on 20 April 2008. The charges were later dismissed due to a lack of evidence.

First Grade Debut: 2004 - Round 21, Panthers vs Bulldogs at Telstra Stadium, 30 July First Hat-trick: 2007 - Round 6, Sharks vs Canberra Raiders at Canberra Stadium, 21 April, scoring three tries in a fourteen-minute period Representative Selection: 2007 - City vs Country at Coffs Harbour, 3 May