jlvfr, thank you very much for your report about the "Victorian Era" wonder in CCM 2.50.
That benefit of this wonder is intended, as there exists no other option than to give a building to all cities of a civ on the world map or on a continent. An option to give buildings only to coastal cities is not existing. As the main benefit of dockyards in CCM 2.50 is to provide an additional shield to every coastal-, sea- and ocean tile, it has no influence to cities, which are completely surrounded by land tiles.
In the next version of CCM, this GW is replaced by the new GW Westminster Palace and the benefits are different, as the dockyards with their production boost in all coastal-, sea- and ocean tiles of a city were too strong.