Really depend on the Rank or person. Junior banker can wear anything, from DW to Oris.
Those on sales or business banking generally wear better.
I have seen Cartier or Rolex for those VPs but some VPs dont even wear watch.
But i realized a trend these days, those EVP or SVP, wear fitbit. CCRO even said: nowadays it is so easy with these little device that it can track your health.