So if this thread has been bumped, does it mean I can now respond to 'old posts' within?
Definitely American. The 'a' in wrath in English sounds more like the 'a' in father.
Depends where in England you come from. Loads of examples:
wrath or wrar-th
glass or glar-se
grass or grar-se
bath or bar-th (that's as in "I'm going to have a bath")
The former is more Northern England, the latter, Southern England.
The "wrath that sounds like the 'a' in father" that you're talking about is RP (Received Pronunciation) which tends to come from those in the South of England.
I'd imagine that Daphne (Mrs. Niles Crane from 'Frasier') will pronounce the cats as kiRAthi.
I'm in the middle of England so my speech is littered with a mix of north and south. I think I actually use both kilRARthi and kilRAthi interchangeably!