Wynn's career WAR of 55.8 (using baseball-reference) puts him in the top 150 all time for position players; this puts him in a cluster of players in the mid-50s that includes some hall of famers and other very well-known players: Will Clark, David Ortiz, Joe Gordon, Hank Greenberg, Joe Mauer, Willie Keeler, Joe Medwick, Luis Aparicio.
https://www.baseball-reference.com/leaders/WAR_bat_career.shtml
For those who prefer Win Shares to WAR, in the 2nd edition of his Historical Baseball Abstract (now 20 years old!) Bill James ranked Wynn the 10th best center fielder of all time, ahead of (among others) Larry Doby, Dale Murphy, Richie Ashburn and SIM-favorite Max Carey.