Abilities » Dance of the Ancients
If I have Tapu Koko {*} and only one other Pokemon on the bench, can I use "Dance of the Ancients" to put 2 {L} Energy on that one other Benched Pokemon?
No, in this case, you can put only one {L} Energy on that Benched Pokemon. The second {L} Energy would have to go onto Tapu Koko {*}, but then gets discarded immediately anyway when Tapu Koko {*} goes to the Lost Zone.
Source: Team Up FAQ (2019-01-18), TPCi Rules Team (2019-01-31)
Abilities » Dance of the Ancients
If I only have one {L} Energy in my discard pile, can I use Tapu Koko {*}'s "Dance of the Ancients" Ability to put it on one of my Benched Pokemon?
Yes, you would do as much as you can.
Source: Team Up FAQ (2019-01-18), TPCi Rules Team (2019-01-31)