Is there a relationship between bond strength and polarity? I believe that a more polar bond would be stronger, since it would be similar to an ionic bond.

However, this seems to be wrong when applied to the study of acidity of some compounds.
In terms of acidity, ionic(polar) bonds dissociate more easily than covalent(polar) because the electrons are shared less equally in the ionic bond leading to easier breaking apart of the molecule. An acid for with an ionic bond will dissociate more easily leading to a stronger pH than an acid with a covalent bond.