The stand-in coach believes the Reds are forging a noted reputation in Asia, having met their goals of the group stage with one match still to play
United's positive continental run continued with a 0-0 draw with Uzbek champions Bunyodkor at Hindmarsh Stadium on Wednesday, meaning they have lost just once in five Group E matches.
They lead the group on 10 points, with K-League outfit Pohang Steelers in second and a point in arrears.
United face a tricky trip to the group's bottom side Gamba Osaka of Japan in the final matchday, on May 16, while Bunyodkor host Pohang.
But with their place in the knockout stages already assured, it was a delighted Trani who spoke after the match.
"We've qualified for the second round of the AFC Champions League so the objective was pretty much achieved... which is a good thing," said Trani, who had the reins of the Reds as head coach John Kosmina is still without the required coaching qualifications.
"It's a great achievement... it has been a success. Some tournaments around the world, clubs will always try to do everything they can to win every trophy but sometimes it's too difficult.
"We're in this particular competition now that we find ourselves in the top 16 clubs in Asia and that's a huge benefit to the club. The branding of Adelaide United continues in Asia and that's a reputation that will hold for years to come."
Trani said Bunyodkor had made it "very difficult" for his side in the 0-0 stalemate, but praised the Reds' discipline.
"It was one of those games where they were very good and we had to be really on our game to make sure that we didn't get ourselves punished in any way," he said.