The carbon-oxygen bond in phenol

(i) Due to the resonance, it develops a partial double bond character in carbon-oxygen bond. Thus, the decrease in the size of the carbon-oxygen bond in phenol.

(ii) In phenol, Oxygen is directly attached to a sp2hybridized carbon atom, whereas in methanol, Oxygen is directly attached to an sp3 hybridized carbon atom. Thus, the bond formed between oxygen and sp2 hybridized carbon atom is slightly stronger than that in methanol.