Did the French poison wells in retaliation for the bombing of French cafes in their north African colonies?

The most definitive answer I can give you is probably. 
The center of anti-French sentiment and resistance in the 1950s and 60s was in Algeria,
home to 8 million Muslim-Algerians and 1 million colons, or long
term French settlers.

This forgotten conflict, a rebellion
that lasted from 1954 - 62, was as bloody, ugly and brutal as any that have been fought
between empire and colony.  Bombings and assassinations were used by both the FLN
(Muslim rebel group) and the SAO, the Secret Army Organization, formed by hard core
right wing former Army General Francoise Sagan, who was both pro-French Algeria and
anti-Chares de Gaulle (The President of France, who wanted to let Algeria have
independence).

Torture, imprisonment in Algeria of 1
million people in internment and "regrouping" camps, assassination, and every other ugly
tactic were used by the French Army, the SAO and the
FLN.

With further research I came across some very good
articles on this conflict, but found no specific instance or reference to the poisoning
of wells.  The most likely time this would have happened is when the French Army
relocated civilian populations to camps and then wanted to deny water to the rebel or
remaining civilians sympathetic to the FLN.