Thanks to everyone for the excellent responses thus far!
It certainly does appear that corrode effects and piercing may be effective tactics against the problematic conjurations. Vorpal Blade and Critical Strike, if included in Forged in Fire (FiF), present a mana efficient opportunity to take out Wizard's Tower or Gate. With few exceptions (mainly Brogan) we have not had this to date. Ballista may also provide a breath of hope for the war school by encouraging mages to set up shop in the middle of the board and pound bolts at guys and conjurations alike.
How do I (try to) beat the Wizard? At the moment, it's by taking advantage of the Druid's access to excessive equipment and armor destruction effects that do not sacrifice spellbook points. 6x Dissolve, 4x Acid Ball, and several Corrosive Orchid's allow me to burn wands and melt armor all day long. The Druid can also hem in the teleporting to some effect by establishing efficient threats (Raptor Vine) on the board that may not be anywhere near herself. A treebonded Druid has good channeling and a great spawnpoint in Vine Tree that lets you wrap around the board very quickly and free up actions.
Provided that I can exhaust my opponent's teleport effects and wands through attrition and not die in the process, I outrun the slow guys with Elusive, neuter them with Agony, and slap on Barkskin or Regrowth Belt mid to late game if needed to regain health. Raptor Vines or Grizzly usually do the heavy hitting. At all costs, you cannot let a Hydra get to your Treebond, so pack Teleport accordingly and keep the Wizard skittering around at the other end of the board. Devouring Jelly is also great for tree defense if needed.