Thanks for this - I head for that train occasionally as it's less disruptive to change trains close to the start of a trip rather than in the middle, and sometimes had good availability of advance fares. That's another I'll strike off the list. :-(

 
South Western Railways are not running the 07:42 through service from Westbury (07:50 from Warminster) to London (Waterloo) at the moment.  The train still runs as far as Salisbury but it's terminating there at 08:11 and another train leaves at 08:15 for London.  The connection is too tight to be "official" and so the journey planners do't offer it ... the journey is possible via Salibury, officially, by leaving Westbury 45 minutes earlier or leaving  Salisbury 30 minutes later.

Research suggests that the train via Warminster is terminating at Salisbury because the train that it used to couple up with via Gillingham now starts back at Exeter and is longer (temporary WoE timetable), and that the loss of the through morning train from some West Wilts stations to Waterloo is a consequence - same number of carriages as before into Waterloo.

I am open to opinions as to whether this change is an unplanned side effect of the temporary timetable, or if it was appreciated that the connection / travel opportunity even with a change was being withdrawn by SWR when they drew up the temporary timetable.