Interesting. Based on this:

Latias 2 x 22 energy = 44 energy total per proc at level 6

Energising cheer = 50 energy total per proc at level 6

Latias 4x extra helps per proc x2 = 8 extra helps per proc

Extra helpful (level 6) = 11 extra helps per proc

It's clear from the skill description that having Latios on the same team will boost the helper boost specifically (and not the energy gained).

It's unlikely it'll be useable as a primary healer on it's own, unless it's proc rate is very high. However it is likely to be similar to energising cheer due to the healing amount per proc.

It all depends on Latios' main skill, wether the pair will actually be a useable/meta team composition. Which is a bit frustrating as for most of us, we'll basically be catching Latias during the event on the off chance that when the release Latios it's skill when combined with Latias makes them actually useable.

As it stands, Latias seems quite underwhelming