Phillips was not involved in the Three Lions' friendlies against Switzerland and Ivory Coast in March due to a hamstring injury, but he has now returned to the squad after proving his fitness for his club at the end of the 2021-22 campaign which culminated in Leeds staving off the drop on Sunday.
Meanwhile, Bowen has been rewarded for an outstanding campaign at West Ham, with Leicester City defender James Justin also handed his maiden call-up.
Liverpool captain Jordan Henderson, Aston Villa skipper Tyrone Mings and Arsenal youngster Emile Smith Rowe were absent from the 27-man selection and there was no recall for in-form Leicester playmaker James Maddision.
Former Hull loanee Fikayo Tomori, fresh from winning Serie A with AC Milan, had also been included in the Nations League squad.
Bowen and Justin were the standout inclusions in Southgate's squad for the four Nations League games, with trips to Hungary and Germany followed by Molineux encounters with Italy and Hungary.
After a foot injury prevented him receiving his maiden senior call-up in March, Bowen was included having finished a fine season with 18 goals and 13 assists in all competitions.
Versatile full-back Justin was a more surprising inclusion. The 24-year-old has made 19 appearances in all competitions since recovering from an anterior cruciate injury sustained in February 2021.
On the reason behind Bowen's call-up, manager Gareth Southgate said: "Constantly strong performances. We were certainly thinking about involving him in March before he got injured.
"He's a goal threat and his direct journey is an interesting reminder that you don't have to be at an elite academy - experience is a great route to go.
"He works incredibly hard for the team, which we want all our players to do. He thoroughly deserves his call-up."
England are scheduled to play Hungary twice, plus Germany and Italy, between June 4-14.
Alongside Phillips, the other Yorkshiremen in the squad are Harry Maguire, John Stones and Kyle Walker.
Squad: Goalkeepers: Jordan Pickford, Nick Pope, Aaron Ramsdale.
Defenders: Trent Alexander-Arnold, Conor Coady, Marc Guehi, Reece James, James Justin, Harry Maguire, John Stones, Fikayo Tomori, Kieran Tripper, Kyle Walker, Ben White
Midfielders: Jude Bellingham, Conor Gallagher, Mason Mount, Kalvin Phillips, Declan Rice, James Ward-Prowse
Forwards: Tammy Abraham, Jarrod Bowen, Phil Foden, Jack Grealish, Harry Kane, Bukayo Saka, Raheem Sterling.