As Super League champions Bradford faced National Rugby League premiers Wests Tigers in the 2006 World Club Challenge. Vagana played from the interchange bench in the Bulls' 30-10 victory. A destructive tackler and strong runner with the ability to off load the ball, Vagana rarely missed a game for the Bulls and became one of the most popular players at the club. He also wrote a weekly column for several Bradford newspapers and the Bulls website. In 2006 Vagana was awarded the Bulls Clubman of the Year Award. He signed a one-year extension on the 18 August 2006 to keep him at the Bulls for the 2007 season. After a long absence he was called up by New Zealand for their game against Great Britain in 2006 but did not play in the match. In June 2007 Vagana signed another one-year contract with Bradford, signalling his intent to play out the 2008 season. Vagana was sent off for the first time in his Bulls career against Wakefield Trinity Wildcats on 5 August 2007. In August 2007 he was named in Bradford's team of the Century. In 2008 whilst playing for Bradford against Wigan Vagana broke his arm attempting to tackle Stuart Fielden. Vagana retired at the end of the 2008 season after 8 years with the Bulls. In 2009 and 2010 he coached the East Coast Bays Barracudas alongside Willie Swann.