Antonelli, the youngest F1 championship leader and first Italian to win twice in succession since Alberto Ascari in 1953, leads experienced teammate George Russell by nine points.
"When it comes to Kimi, we've always been very clear in our objectives," Wolff told reporters on a video call.
"Our first learning year with great performances, highlights, and then other moments where it's going to be very difficult. And we've exactly seen that.
"And now we're in the second year, and he continues to develop in a way that we have hoped to see and forecast.
"Of course, in Italy everybody wants to talk about world championships and comparisons to (late Brazilian triple champion Ayrton) Senna come up, which is something which I don't enjoy reading because he's a 19-year-old."
Wolff praised Antonelli's handling of the pressure.
"He copes very well," he said. "I think in the team, there are times when we put our arm around him. Other times, we exercise more pressure. But overall, everything is coming together as expected."
Wolff said Russell, who started the season as title favourite and team leader on track, had been unlucky after winning the opener in Australia.
The Briton started and finished second in China after a problem hit his qualifying, and he then had to fight back after an early safety car period left him second in the queue for fresh tyres at Mercedes.
In Japan, Russell was fourth after the safety car was deployed just after he had pitted while leading Antonelli, who had yet to come in for fresh tyres and did so while staying ahead.
"I haven't seen many mistakes that George has made until now, but I have seen races going against him that he could have won in safety cars or being stuck in traffic," said Wolff.
"He's driving on such a high level, he's instrumental to the team's success. He's a great character. He's a Mercedes driver, and we can see that."