Trainers » PlusPower
Does a PlusPower work with Hitmonlee's Stretch Kick attack?
It does not. Pluspower only adds to the total if the attack does damage to the [Active] Pokémon only.
Source: WotC Chat (2000-05-11)

Relevant cards

Note: All applicable cards may not be listed below.
WOTCB1_84
WOTCB2_113
WOTCB2_113
BW1_96
DP1_109
DP3_121
HGSS2_80
PL1_112