First off, Landmarks are NOT used to mark Points of Interest (POIs).
Waze does not maintain a POI database, you have to correct this issue with the third-party search provider that gave you your results (the tabs at the bottom of the in app results screen). Waze only gets GPS coordinates and navigates to the closest segment to those coordinates. For more, see item #27 of the Waze FAQ.
Also, for the US, see the near-final US Landmark Guidelines