The program of the "Pops" concert at 8.15 o'clock tonight in Symphony Hall follows: 1.  Prologue to "Pagliacci"  Leoncavallo 2.  Waltz, "Dream of Love"  Fahrbach 3.  "Devotion"  Herbert 4.  Fantasia, "Manon"  Massenet 5.  Marche Slave  Tschaikovsky 6.  Berceuse  Johns 7.  Overture to "The Bat"  Strauss 8.  Bentley School Songs   9.  American Military Fantasy  Rollinson 10.  Waltz, "Spanish Serenade"  Metra 11.  Slavonic Dance, No. 7  Dvorak