I have not gotten that far yet, but from a couple comments in the forum I think the best strategy is to fly ahead of the zeppelin along its intended flight path and use the new spell on the nests to take them and the surrounding towers out.

If you are not already playing on casual, you could lower the difficulty setting.

Flames of Vengeance Zeppelin Escort


I don't know if the new skill has a pre-set hotkey, or if you should be able to assign it like you do most other dragon skills (for the Xbox version hold down a button or d-pad direction, or one of several methods on the PC).