It's only useful if at the same time you send attacks to target the corresponding supplies at airfields close to the front.
e.g. flatten the refinary and kill the fuel supply at a field, it will be unusuable for 2 hrs (vs. 30 minutes with refinary up).
The only two factories it makes sense to hit at all ihmo are the refinary and the grunt training facilities. Of course, hitting them without also targeting the fields is useless.
Also, this isn't really useful if you want to actually capture the enemy field, but to make him stop from taking yours. On the maps with strat zones its far easier to let the enemy capture the first row of fields in your zone, then rebuild time is maxed automagically.