No I don't think so.
In fact I think Ground Beneath her feet is a rare example of where U2 wrote the tune specifically for the words.
If you listen to studio sessions like the salome outtakes (in particular), and even more recent songs like native son-vertigo, it's clear that chord structure and basic guitar riffs are often worked out well before the melody & words are finalised.
Ground beneath her feet is one of the very few U2 songs that wasn't written by the band (salman rushdie wrote it) So I'm guessing that for once they had to compose the tune to fit the lyrics.
Of course, We all know that they can have ideas for songs knocking around for years before they actually use them, so there may be influences from flower child, but in this case IMHO I don't think so.