I am searching for any type of recording for the instrumental 'Bakom.'
I believe it was composed in the 60's or 70's though I don't know by
whom. It is on the soundtrack and played on the harmonica near the end
of the Eric Serra film 'Jet Lag' with Jean Reno and Juliette Benouche
(I believe in 2002). I remember listening to it as a teenager (and not
knowing the title then) and loving it.  I heard it recently, 30 years
later, in the film and have had no success finding anything on it. Can
you help?

I think you may be referring to 'Everybody's Talkin'' which was
written by Fred Neil and originally recorded by Harry Nilsson in 1967.

It is probably best known for its inclusion in the movie 'Midnight
Cowboy' in 1969, where a version was performed on the harmonica by the
Belgian-born jazz virtuoso, Toots Thielemans.

The track 'Bakom' was written by Eric Serra based on the Midnight
Cowboy theme, also employing the talents of a Belgian harmonica
player.

However, the director of 'Jet Lag' ('Decalage Horaire'), Daniele
Thompson, decided to go with the original version in the movie.

Serra's version is only therefore available on the movie soundtrack album:

http://www.amazon.fr/exec/obidos/ASIN/B00006RZ67