Can I use Emolga's "Bounce" attack if I have no bench?
Yes, you do as much of the attack as you can. First you do the damage, then you perform the switch if Emolga is able to go to the Bench.
Source: Next Destinies FAQ (2012-02-09), TPCi Rules Team (2012-02-09)

Relevant cards

Note: All applicable cards may not be listed below.
BW4_49
PL2_59
PL3_94
HGSS1_67