At what elevation and temperature will pomegranate trees grow?

http://edis.ifas.ufl.edu/MG056

Pomegranates grow in zones 7 to 24 and possibly in zones 5 and 6 if
grown against a south or west wall. They thrive in the heat and need
long hot summers to produce well. They tolerate many soil types
including very alkaline soils but deep loams are best. They are
drought tolerant but need regular deep irrigations for good fruit
development. They tend not to fruit too well in cool coastal areas.
Pomegranates are hardy down to 12 degrees F. roughly. If grown in a
container they can be brought indoors during cold weather or grown in
a greenhouse.

Info obtained at:
http://www.olive-trees.net/pomegranate/treecare.html

Re: elevation, I found this (this site also had some great planting and care tips):
While trees are hardy and can withstand cold temperatures, they are
not recommended for higher elevations where late frosts can kill the
new growth and flowers. They prefer the warmer climates and are very
drought tolerant. Trees are deciduous and grow to 15 feet.

http://armstronggarden.com/caresheets/caresheet_pomegranates.html

Good luck!

Pomegranates grow at 6000 feet if it is warm and they get water.  We
have some in Mexico in the mountains.  I do not think this is a limit,
though, just pointing it out since I know.