What vowel do you have in the first syllable of "Alma"? [A], [{], or something else? LPD gives only /"{lm @/ but I think I've heard ["A:5m@] or even ["Q:5m@] from NA native speakers.
"Alma"
I myself pronounce "alma mater" as ["Q:U~m@:"ma4R=:], if that is what you mean by "Alma" here.
I was actually thinking of the word used as a proper name (I think especially in foreigners, but an American girl happens to have this as a first name in my workplace).