Situation: my opp. has a multi energy on his /her active pokemon , can I use swim 's attack effect to do damage to their bench pokemon . I say yes because the wording say (water ) energy -not card
Ah.
You are correct, but you are keying off the wrong thing.
It's not because it doesn't say "card".
It would be OK if it did.
What is important is that it doesn't say "basic Energy".
It's the "basic" that would exclude Special Energy cards such as Multi.
Multi is still a card.