Oh, this is interesting! I had a look in the 1967 catalogue, and City of Tomorrow is present, listed as a track from DW/LP 2988:
But looking at Discogs, there's no such title on DW/LP 2988:
h++ps://www.discogs.com/release/3831795-The-International-Studio-Orchestra-The-Power-Game
The opening track, the theme music to
The Power Game, is by Wayne Hill and is the same running time as City of Tomorrow, so it looks like you've stumbled on the original title of The Power Game theme. I'm not sure if anyone knew this before today (I didn't anyway)!