It's a bit misleading to compare a pine that's been in cultivation for a hundred years with anything. Such a tree is without compare, however, more than one artist is involved with such a plant and no single one can call it his own. It is a cumulative thing, as you have said, that can't be equalled elsewhere. However, the raw material that's being made--or redesigned or maintained-- into bonsai now in Japan can certainly be equalled by many across the globe. Bonsai in Japan is, like many cultural arts there, in somewhat of a decline.
Some in the U.S. are making use of excellent material and making something of it.
http://elandangardens.com/bonsaigarden/tree95.htm Artists here are also pioneering some pretty advanced techniques on native species
http://www.bonsai-wbff.org/nabf/new...2/bcarticle.htm
Same is true for Europe and Southeast Asia.