It would be good if you could have a box with bottle(s) in it and you pick them up, for example your max jet pack bottle limit is 3, 100% (jet-pack use) 12%, (when 0% is reached another bottle will be needed, if you dont have any you must pick a box of them up.
Another way of doing this is having an object for Alpha, Bravo etc. where only that team can recieve a boost of jets (like a bottle). So in Alpha base is a tank, and in Bravo base is a tank. Although when you use your jets they dont just refill.
A new power-up could be added too, if you were to have Mad Jet mode, where you have infinite jets and there twice as powerful.