http://www.bbc.co.uk/news/uk-england-somerset-18280324
AD 274 (the date of the latest coin in the hoard) is of course the year after Aurelian reconquered Gaul (and, by extension, Britain). The coins in the photograph look middle third century.
That said, not all the coins have yet been checked, so the hoard might have been deposited in any of a number of eventful periods following AD 274. The lack of Carausian coinage (unless there is some among the coins as yet unchecked) would narrow the field somewhat.
What is evident is that the depositor did not live to collect it.
Patrick
Interesting blog on the restoration/excavation here:
http://blog.britishmuseum.org/category/conservation-2/beau-street-hoard/
It's interesting to speculate on where the 32BC 'Mark Anthony' had been before ending up in a hole in the ground in Britain. Likely to have been in circulation for 3 centuries!
The fact that the coins are bagged by denomination (at least in the case of those so far examined) suggests a merchant's hoard, as does a stone receptacle (an army paychest would presumably be made of a lighter and more travellable material). So far there is no indication of gold coins (though who knows what may lie in the unexamined bags at the base of the agglomeration), which raises the possibility that what we have might perhaps be the 'takings' from the baths themselves stored in an official's basement.
No seals have survived (coin bags would usually be sealed for reasons of record-keeping and honesty), so this is pure guesswork and by no means the only interpretation.
Patrick