They're supposed to be here
http://www-odi.nhtsa.dot.gov/cars/problems/tsb/tsbsearch.cfmbut it's fee based to see what they're about
NHTSA item 10019987 seems to bring up most of the Triumph issues, then one can muddle their way through their specific year and model.
It is at best, a database of little public info on the surface, unless one wants to spend the $37 per hour to dig deeper. Sometimes you get lucky and can cull a bit from the summary:
Make: TRIUMPH
Model: DAYTONA 955
Year: 2004
Service Bulletin Number: 09012005
NHTSA Item Number: 10018150
Summary Description:
THROTTLE POSITION SENSOR INNER O-RING. DAYTONA 955I, SPRINT ST 955I,
SPRINT RS, SPEED TRIPLE 955I (ALL 2002 MODEL YEAR AND ONWARDS). *NM
'Funny' how the folks who fund it have to pay to use it...