wisdom tool-tip says its equal to max spell points. It appears that wisdom stat does not affect mana (there is no spell points in the interface only mana. I am inferring that 'spell points' needs to be changed to 'mana' if it is supposed to impact that stat.)
max mana appears to come from intelligence.
There is a correlation between wisdom and what spells can be learned. but I can not figure out the link. I can only decipher that if you have 5 wisdom you can not actually learn any spells until you learn 'reach spell level 2' at which point you can learn level 1 and level 2 spells. Maybe wisdom and intellect tool tips are reversed?