Bleaksoul posted this in one of the threads and I thought it worth a discussion.
Yes you do. From the codex. "If a model with a webway portal is in Reserves or Ongoing Reserves, then the model and any unit it has joined or is embarked upon has the Deep Strike special rule. This model, and his unit, will not scatter if arriving from Deep Strike Reserve." Therefore the unit (the firedragons ) and the archon can deep strike without scattering but the vehicle will still scatter. The vehicle is a different unit from the one the model is attached with which is why we can jink and shoot the guys inside at full BS and why the vehicle can shoot at a separate target from the guys inside. The webway portal only allows us to deep strike vehicles that normally cant like wave serpents.
http://www.thedarkcity.net/t11599-dark-eldar-w-eldar-allies-all-comers-list-w-solid-airpower-competitive
I figure it should be discussed here as opposed to someone wanting C&C on their army and getting a totally off topic discussion.