Public transport services over the Bank Holiday weekend are as:

Saturday August 28th
Buses and Trains: Normal Saturday Service

Sunday August 29th
Buses and Trains: Normal Sunday Service

Monday August 30th
Buses: Sunday Service
Trains: Saturday Service

There are no planned railway engineering works over the holiday period that affect the trains through Whitchurch.

…and some good news:
Meanwhile there is some good news from Stagecoach on the bus front.
The buses based at Andover for the 76/86 route are gradually being replaced by newer low-floor double deckers. Hopefully all buses on the route will have this easier accessibility by this Autumn.
The buses are also to be branded to the route, so as the promote the service.

Public Transport contacts are available HERE