Can I choose one or more parts of Greninja V-UNION with Vaporeon VMAX's "Bubble Pod" attack, and play it on my Bench?
Bubble Pod cannot put Greninja V-UNION into play because Bubble Pod will only get one card of the V-UNION, and one piece of a Pokemon V-UNION cannot be brought into play alone.
Source: TPCi Rules Team (2021-09-30)

Relevant cards

Note: All applicable cards may not be listed below.
SWSH7_30
SWSH7_30