Plan for this coming Saturday

9.55 Train from St Davids to Bristol Temple Meads. Arrive 11.16

Knights Templar (JDW) for late breakfast if required (or could catch 11.46 on to Clifton Down).

12.12 Train from T.M. to Clifton Down. Arrive 12.26

Pubs in this order:
Brewhouse & Kitchen, Good Measure, Chums, Hillgrove Porter Store,
Hare On The Hill, Crofter Rights.
After this, depending on the time and peoples' capacity, further visits possible
are New Bristol Brewery, Swan with Two Necks, Volunteer Tavern and the Barley Mow.

That is probably too long a list and quite a lot of walking is involved.
Trains back from T.M. are 5.45, 6.53, 7.45 then not till 9.45.

I suggest you buy split tickets:
1) a day return from Exeter (or in some cases Exmouth) to Taunton
2) a day return from Taunton to Clifton Down.