Jason Deamer has raised the bar for unbeaten sprinter Bon Amis as the Newcastle trainer makes a rare excursion to Sydney.

Deamer, who has only had two city runners this year, tests Bon Amis in Saturday city company for the first time when the four-year-old lines up in the Cellarbrations Handicap (1100m) at Rosehill.

A convincing win first-up in Newcastle last month earned Bon Amis a metropolitan start and Deamer is confident the four-year-old would justify his $1.80 favouritism.

Deamer said a 4-3/4-length victory over 900m on his home track on October 21 pointed to Bon Amis improving on stablemate Serious Hoffa's runner-up placing at Canterbury in August.

"The race has fallen away, it's a small field, nice barrier, nice weight," Deamer said.

"He'll improve on his first run back, he should be hard to beat. We'll give him chance in in Sydney and see how good he is."

Bon Amis had his first start in May at Cessnock and he also won at Muswellbrook later that month before going for a spell.

"He's improved with every run and he's returned stronger and more mature," Deamer said.

Deamer has 11 horses in work and rates Bon Amis as the pick of his stable, a view that has changed over time.

"I didn't have much of an opinion of him, he's easily at the top now," Deamer said.

Bon Amis made his way to Deamer's operation after main owners Gary Sheppard and Tom Bremner purchased him for $4000 while they waited for a yearling to become race ready.

Bon Amis could be a lucrative stop gap measure who has returned $39,030 in his three starts.

Bon Amis jumps from barrier one with Rory Hutchings, another positive for Deamer.

"That shouldn't pose a problem for Rory, who's an underrated rider," Deamer said.

Deamer said his next move with Bon Amis would be governed by his performance at Rosehill, but he anticipated stretching him out in distance.

"I don't think he'll have any trouble getting 12 or 1400 (metres) later on," Deamer said.