If two species form a hybrid, with certain characteristics, and then in a
completely different locale, the same two species independently form a hybrid,
with different characteristics, are the two different hybrid forms the same
species?

As far as I know, they would carry the same hybrid taxon name, but they would
be listed as different cultivars.

Iris,
Central NY, Zone 5a, Sunset Zone 40
"The trouble with people is not that they don't know but that they know so much
that ain't so."
Josh Billings (Henry Wheeler Shaw), 1818-1885