The Cherries grabbed an early goal through Mikael Ndjoli’s 11th-minute strike but Fletcher’s men soon struggled.
Wolves responded either side of half-time thanks to goals from Sylvain Deslandes and Morgan Gibbs-White.
Goalkeeper Aaron Ramsdale and Shaun Hobson produced strong performances and Fletcher believes they can bounce back.
He told the club’s official website: “Wolves are a category one side so are used to playing in stadiums and playing in front of people.
“We were disappointed with the result and to lose late on, but it is all part of the process.
“Players will make mistakes but it is important that they learn from every game. They have to take things like this on board then, in the long run, it is a positive.
“We need better quality in possession and games sometimes don’t go your way. But it was another game that the players can learn from.”
Paul Huntington says Preston's play-off hopes this season hinge on them getting the balance right on and off the pitch.