I didn't learn Wisdom or do the battlefield dungeons in BD. See how you do in higher level dungeons, or back in the main game, and stop investing in Wisdom if you remain a higher level than the majority of your opponents. Without Wisdom you would still be the same level, though (or possibly 1 lower if you recently levelled).
I learned Wisdom in Divine Divinity, but even learning each level as soon as possible would only give you one extra level by the end of the game, with a typical final level in the mid forties to low fifties (Wisdom - is it worth the skill points?
). In Beyond Divinity, you need twice the skill points, for both characters, to get the same bonus, and the end level is lower (about 29) so you will not get an extra level. You will level slightly faster, though, and since you can unlearn skills, any unneeded free skill points are better put into Wisdom than left unused.
There were some complaints in the forum when the game was first released that you had to level in the BF dungeons, and there were too few skill points, so I avoided the dungeons and hoarded skill points (and finished the game just fine).