Ian Jelf wrote

Free to pass holders, but I understand the District or Borough where
they get on will have 60 fares to pay to the bus operator from their
budget.

That will be a distinct shock to the sightseeing operators, I
suspect!

http://www.surreycc.gov.uk/sccwebsit...pWebPagesByTIT
LE_RTF/Notification+of+arrangement+for+concessionary+bus+ scheme+for+Apri
l+2008?opendocument

Reimbursement for local bus operators participating in the scheme will
change from the current mileage based scheme to one based on the
numbers of permit holders boarding within the county. Further
information on claiming reimbursement is contained in a separate ‘Notes
of Guidance to Operators’ which will be issued to operators
participating in the scheme.

Concessionary Fare Permits are not valid on this service
This service is supported by Royal Parks and Savill Garden

Yes I noticed that last year. It made me wonder at the time if
operators *can* choose to opt out of accepting concessionary passes
on
commercial services.

From the document above

Permits cannot be used on:
Services of limited duration, or to special events
Long distance express services, such as operated by National Express
Services other than bus services (such as tram, railway)
Services in Wales, Scotland or N. Ireland
Services which the Department for Transport may from time to time add
to the
above listing.

So "summer only" might count as "limited duration" otherwise a ukase
from the DfT will be needed.

--
Mike D