I believe that in some cases a difference does exist. Differences exist between between companies on how and where tobaccos are blended. From what I recall sometime back while doing some research and I believe it was with Orlik, that the tins were made in Europe and the bulks are produced in the USA. The same was true for other companies as well. That would mean tobacco from different areas were used to produce the same blends. IMHO, that would mean that there would be minor differences in the flavor profile of the tinned tobacco vs the bulk tobacco.

Also, the flavors of tinned tobacco will mature much more quickly that bulk tobacco.