"tomato" is always pronounced "tomato", no matter how you pronounce it. The same is true of all other words.

For example, Tim Laycock was saying at Whitby that he'd found that, if you wanted to get Dorset people to pronounce the poems of William Barnes (Linden Lea and so forth) in proper Dorset, the thing to do was to scrap Barnes's valiant attempts to write them down with a spelling that attempted to reproduce the accent (see that website I gave the link to), and instead to write them down with standard spellings, and leave it to the reader to pronounce the words the way they talked.

One of the advantages of spelling in English not being consistant and logical is that it lends itself to this kind of flexibility. I believe that a strict phonetic spelling would tend to stamp out local variation far more effectively.