What's sure is they weren't in the original PC88 game.
Since they were composed by Masaaki Kawai who apparently joined Falcom around 1989 when Ys 3 was released, there is a chance he actually composed them for the PC88 game and they were only included in later ports ...
Since they're the only Ys 3 tracks composed by him, there's also a very high chance they were composed only for the X68K port, and adapted in PC88 form for the PSP emulated version to fill the holes ...
Both work imo. Not that important anyway, but it's fun to nitpick on that stuff, isn't it ? ^^;
__________________
|