if ravenbloom student is at a battlefield and temporal breach is played from hidden targeting it, does ravenbloom student get the additional might from a spell being played?

Yes — Ravenbloom Student gets +1 Might.

Playing a spell from Hidden still counts as playing it (FAQ #1301). Temporal Breach resolves by banishing the Student, then its owner plays it back to the same location — so when the spell finishes resolving, the Student is back on the board, and "when you play a spell" is evaluated at that point. The trigger fires and the Student gets +1 Might this turn (FAQ #5601).

One edge case: if the Student was the only unit at that battlefield, its owner loses control of the battlefield when it's banished, so the replay instruction fails and the Student stays banished (FAQ #4383). With the Student no longer on the board, the trigger does not fire.