The Leeds academy product appeared to be at risk of missing out on Wane's 24-man squad for the three-Test series against Tonga when the England boss said he would not entertain his lapses in discipline.
But injuries to Herbie Farnworth, Jake Wardle and Mark Percival opened the door and Newman grasped his opportunity to end a challenging season on a high.
The 23-year-old scored England's final try on home soil at Headingley as Wane's men claimed a 26-4 win to complete a series whitewash.
"I'm really happy with him," said Wane.
"He's been under the pump. We've had some really, really honest chats and the way he's responded, Leeds have got a good player there.
"He's a really talented player and showed that with some of the things he did today. A couple of things were a bit off but his attitude and behaviour in camp has been so good.
"He's a credit to Leeds Rhinos."
Wane also praised Hull KR half-back Mikey Lewis – who made way for the returning George Williams at Headingley – and former Wakefield Trinity winger Tom Johnstone, as well as Player of the Series Harry Smith.
"Harry and Mikey were the number four and five half-backs but they're not anymore," added Wane.
"They've been outstanding and done really good things. They'll go from strength to strength.
"Tom Johnstone is another one. We had a choice of wingers with Dom Young being out and you look at what Tom has done – stopping those two tries last week. There are not many wingers that could have done what he did.
"I've got nothing but praise and I've just said that to the players."
After winning the series with victories in St Helens and Huddersfield, England saved their best performance for Headingley.
Ben Currie finished a slick team move to open the scoring, a try that was arguably topped by Newman's effort at the end of a scintillating passage of play.
Matty Ashton made it three tries in two games, while veteran Bradford-born forward Elliott Whitehead scored on his final international appearance.
"The conditions were a bit firmer and drier than the first two Tests and we played a bit more rugby," said Wane.
"I so badly wanted to win this game. I was desperate for 3-0, especially for Elliott Whitehead.
"I'm unbelievably proud of what we've done and how we've done it. We've had a few players pull out so we could have turned out a stronger squad – but so could they."
The series win – coupled with the mid-season rout of France – has lifted England's spirits after last year's shock World Cup semi-final exit at the hands of Samoa, who will provide the opposition in 2024.
Wane has stressed that the clean sweep against Tonga does not ease the pain of his Emirates Stadium experience.
"Definitely not," he said. "That will always haunt me.
"It doesn't make it better. I'm just happy we've won three Tests."