The midfielder, who joined Bolton ahead of the 2011/12 season on a free transfer after his contract with Swansea City expired, made a total of 32 appearances during his first season at Macron Stadium.
He also scored his first Wanderers goal against his former employers in the 2-1 FA Cup Fourth Round victory in January 2011, before scoring in each of the Whites' opening two Championship fixtures of the 2013/14 campaign.
However a shoulder injury suffered against Watford in February 2014 saw his campaign ended prematurely.
The midfielder previously made 199 appearances during a five-year spell with the Welsh outfit, scoring 31 goals. His last outing for the Swans was in the npower Championship play-off final win over Reading at Wembley that secured the club’s promotion to the Barclays Premier League.
Before his days at the Liberty Stadium, London-born Pratley progressed through the youth setup at Fulham, before enjoying regular first team football out on loan with Brentford.