Does Drifblim's "Drifting Balloon" Ability affect the attacks from the Drifloon beneath it when Celebi EX with "Time Recall" is in play?
Yes, the attacks used from Drifloon will cost one less energy for each of the opponent's Team Plasma Pokemon in play.
Source: TPCi Rules Team (2014-05-08)

Relevant cards

Note: All applicable cards may not be listed below.
BW10_35
BW7_141
BW7_9