[greffov]

tar itself can't do it, but I would do it using find. Find can handle regexps.

see man find especially the OPERATORS section.

one example from the manual:
find / \! -name "*.c" -print
Print out a list of all the files whose names do not end in .c.

in complete the command would be something like
tar -cvzf myfile.tar.gz `find . -name "bla" | xargs`

for a backup it might be interesting to use the -j flag instead of the -z flag, since bzip2 compression is much better than gzip compression.