Winger Young won the PFA Young Player Of The Year award after an outstanding campaign under Martin O'Neill with Agbonlahor - currently on England Under-21 duty in Sweden - voted runner-up.
The pair will both be candidates for Fabio Capello's World Cup squad next summer if they can repeat their form during the 2009-2010 campaign having already made their senior debut.
Former Villa and England boss Taylor is full of admiration for the duo but knows they will have to move to the next level to combat the greater awareness of their abilities by the opposition.
He said: "With boys as young as Agbonlahor and Young, the chances are, when you've had a couple of seasons like they've had, there is always that distinct possibility that they will level out.
"I'm not saying that will definitely be the case but they can level out and defenders become more used to them.
"They are not as big a surprise to them anymore and they have learned how to play against them.
"Then they have to improve other aspects of their game to combat that."
Young, who made the near £10million move to Villa from Watford two and a half years ago, often found himself double-marked by defenders last season but it did not reduce his potency.