What you are asking - whether smoking can be considered eating/drinking - is actually the subject of a disagreement in the Rishonim. Tosafos (AZ 66b) directly imply that smoking is considered drinking. The Rif (Chullin 32 [in Rif pages]) directly implies otherwise. This all comes to the fore in the Halachic question of ריחא מלתא - whether 'scent is a thing', i.e. when cooking two things in the same oven where there is no transference of flavor but there is a transference of scent, is the scent Halachicly like flavor in that a non-kosher scent can render something non-kosher. The letter-of-the-law as ruled by the Shulchan Aruch and Rema in YD 108 clearly follows the Rif. However, Rema says to be concerned about the opinion of Tosafos unless doing so will cause one a significant loss.
In summary, for those who follow the Rema there would be reason to look at smoking as a form of drinking, and therefore one could posit that unless it is difficult to do so the Rema require tevilah for the hookah. On the other hand according to the other Poskim including the Shulchan Aruch who hold like the Rif, smoking does not constitute any form of eating/drinking, and thus the hookah would not require tevilah.
However, based on my argument here - that something which is not edible is not Halachically called food - one could say that even the Rema will not require tevilah for the bowl that carries the tobacco, though maybe still for thing which holds the water.