Are Great Generals counted as Great People? (In other words, does Philosophical affect them, etc.)
No. Great General's are gotten through combat experience points, not Great People Points. It is the GPP's that are multiplied by PHI trait. GG's production rate is increased by the Imperialistic trait (+100%).
However, a settled GG will also produce +3 beakers under Representation civic, just like a regular GPerson would.