Ich war etwas zu voreilig. Sucht man im Wörterbuch nach "St", findet man einen Eintrag mit britischer Aussprache für "St Nicholas". Allerdings keine amerikanische Aussprache.

And then there’s the surname St John, pronounced /ˈsɪndʒən/.

'Bernhard' with an H is German; in English he's St. Bernard.

https://en.wikipedia.org/wiki/Saint_Bernard_(...
https://en.wikipedia.org/wiki/Bernard

You're right to notice an AE/BE difference in the pronunciation of that name. But is it different for the dog (or the saint of Clairvaux) as opposed to the playwright? I couldn't begin to speak for BE, but Wikipedia gives one pronunciation for 'St Bernard' that clearly isn't AE, so is it BE?

St Bernard BE /sn ˈbɜː(r)nə(r)d/ (???)
St. Bernard AE /seint bərˈnɑːrd/

I feel more secure about the playwright, who follows the usual pronunciation on either side of the pond.

George Bernard Shaw BE /ˈbə(r)nə(r)d/
George Bernard Shaw AE /bərˈnɑːrd/

Sorry, that doesn't really address your question about 'St.' But you already seem to have noticed that in BE it may have no vowel at all, whereas in AE it rhymes with 'faint' (bzw. 'feint').

#4 Wikipedia gives one pronunciation for 'St Bernard' that clearly isn't AE, so is it BE?

In contemporary BE, AFAIK, "saint" always rhymes with "faint", except in some instances of "St. John" (e.g. the name Norman St John-Stevas). I wasn't aware, for instance, that "St. Helena" had a special pronunciation.

I'm sorry, I don't agree. For RP I think the statement in #0 is correct: "Saint/St. als erster Bestandteil englischsprachiger Ortsnamen wird im britischen Englisch regelmäßig zu [sǝnt] reduziert..."

#8:

Re St. Helena: Like #8, I'm not sure where #5's pronunciation comes from. I would pronounce "saint" like "faint", but St. Bernard and St. Helena like "sent".

#10:

#9 Thanks, sebastianW. I don't remember coming across the symbol [ɜː] before.

Sorry, sorry, I seem to have jumbled together two kinds of phonetic symbols, so thanks for clueing me in. I confess I had sort of basteled those together from various parts, because the Wiki article on the name Bernard itself didn't discuss pronunciations. I didn't even notice that the /ɜː/ was facing backwards, since I hadn't ever seen it either. So I thought it must sound like Bern (CH), even though I knew the playwright sounds like Burnard in BE, which was the point I was trying to make. The (r) was just because it's usually omitted in BE, but not always.

Never mind, just forget I said anything -- I didn't mean to confuse the issue.

Edit to my #11: I meant #7 rather than #8.

And of course I defer to the BE speakers on 'St'; my broader point was just that the AE vowel is usually a long A, but that in BE apparently it's often or sometimes a schwa. But maybe that's not right either.

OT: I would write St. Anne St. and consider anything else too foreign or strange for comfort.