Trump would be from Castelia City, in Unova, and live in a tower near Castelia Park.
Nimbasa just south of Entralink park, not Castelia. Castelia is the Financial District, whereas Nimbasa is the tourist-focused Midtown where Trump Tower is located (and Entralink park is Central Park, just north of said tower).
Granted, we don't see any towers in Nimbasa in the game, but we do in the anime and the manga.