Aluko's fifth goal of the season after 16 minutes proved crucial as Hull moved up to fifth but Bruce is still seeking improvement.
"Aluko is a good player and was a delight to work with when he was 16 (at Birmingham, where Bruce was manager at the time)," Bruce said.
"Perhaps it has taken him time to develop and time to grow, but he's a naturally gifted footballer who has been great for us so far and could perform at the highest level.
"The better team won, thankfully, but we just needed a second goal and that has been our Achilles heel at times this season.
"To be fair to Barnsley, in the second half they had better possession, but I still think that we had the better chances.
"It often happens that when you are chasing a second goal things can get a little bit anxious.
"But the defenders have won us the game today, and the clean sheet has delighted me. In the end Ben Amos did not have a shot to save.
"You have to show a bit of resilience in this division. We've had a couple of injury setbacks this week, but to their credit the owners have told me to bring in a couple of players, if I can.
"I'd love to say we're close to doing something, but we aren't at the moment. I won't just bring in players to make up the numbers."