Graham called back about five minutes later to say police units were on their way and reiterated everyone needed to get out of the bar.
A number of police cars showed up shortly afterwards and officers searched the premises but did not find a bomb.
Graham later said he couldn't barely remember the night in question because he'd drunk so much and that he liked to play practical jokes.
But Judge Pippa Sinclair, during her sentencing today, said the joke backfired and Graham had caused chaos and significant financial loss.
Backyard Bar owner, Aman Gain, estimated the hoax cost his company between $4500 and $5000.
After Graham plead guilty, a restorative justice conference was held and he told Gain he was "genuinely sorry" for what he'd done and paid $2000 in reparations.
Graham's lawyer, Miles Beresford, said his client knew he'd been "foolish and juvenile".
"He has a wife and children and just should know better."
Graham has two convictions for impersonating a police officer in 2004, but his lawyer they were historic and his other convictions weren't relevant.
And as part of Graham's bail conditions, he'd stopped drinking which Beresford said had a "transformative" effect on his life.
Judge Sinclair said Graham had genuine remorse and his guilty plea showed Graham had taken responsibility for his actions.
She ordered him to pay a further $800 in reparations and sentenced him to 100 hours' community work and nine months' supervision so he could address his drug and alcohol problems.