We never made a promise to Venat. She made a promise to our WoL, that's all. There is not a single Cutscene where the WoL made a promise. The same happens with Graha he says always we made a promise / he made a promise to us to visit Ishgard together.
I can't find any Cutscene where our WoL made any promise to him or where he made a promise to us. It is kinda irritating. It is like we read a Book and Page 151 is missing.