Name Transliteration

[Altair]

In Cantonese speaking areas (or dialects in similar situations), are foreign names transliterated nowadays into Chinese characters according to Mandarin phonetics or local phonetics? Do educated Cantonese read and memorize such names as if they were written Cantonese, or Mandarin?

I have a separate, but related question. Are Chinese names routinely “translated” into whatever dialect one is conversing in, or is an attempt made to retain the pronunciation of the original? In other words, when Yeung4 sin1sang1 is addressed in Mandarin, is he automatically called “Yang2 xian1sheng5”?

[wix]

I know that in Taiwan it is considered acceptable to use Mandarin pronunciations of place names (when speaking Taiwanese). In fact many young people would be unfamiliar with the Taiwanese pronunciation of some place names.

[Lu]

Most Mandarin speakers don't know the pronounciation of someone's name in his/her own dialect, so they use the putonghua pronounciation.