The vowels in ''trap'' and ''bath''.

Speaking AusE I'm split.

/tr{p/
/b6:th/

X-SAMPA

As well as having a nasal-short A system, the traditional Boston accent also has a trap-bath split similar to the one in RP, Estuary, or AusE.

trap - [tr{p]
bath - [baT]

But notice the use of the Boston [a] rather than [A].

<<Speaking AusE I'm split.

/tr{p/
/b6:th/>>

Makes sense. Of course as you surely know the origin behind your split with those words is different, having arisen in an 18th century change of /{/ --> [A] (and then [6:] for modern AusE) before some sounds like fricatives in British English (and AusE by extension, as Australia was mostly populated after this change had occurred), while North American English mostly kept the traditional /{/ forms of 17th century British English and before, as still survives today except for the more recent tense-lax distinction as seen in some dialects as New York. I guess my dialect hasn't really innovated on this particular feature, as it follows the same patterns English has had for those words for many centuries.

<<No, they both have the same vowel for me: [{].>>

Same for me too, but [a] not [{]. (Northern England)