You can now use the setHit command to destroy/restore just the "bulbs" by using it in conjunction with light_n_hitpoint where "n" is the number of the respective light on the pole (some like halogen and decor have multiple lights). Until switchLight is re-enabled, I will use this method for my electrical grid simulation.

lightIsOn also appears not to work for related street lamp objects and near(est)Objects related searches do not appear to return results for class "StreetLamp".