Great Western Coffee Shop

I often catch the train from my local station, Bookham on a Sunday. I have an annual travelcard from Bookham to London which incorporates a Zone 1-6 travelcard with route "Any Permitted" printed on it.

Most weekends recently there has been a rail replacement service between Effingham Junction and either Leatherhead, Epsom or unusually today, Tolworth.

Today I decided to travel to Wimbledon. National Rail journey planner suggested the quickest journey would be via replacement bus to Effingham Junction, changing there for a Waterloo service. This is going in the opposite direction to how I usually use my ticket. A much slower service using the replacement bus in the normal direction all the way to Tolworth showed the same price as via Effingham. I found a document on the ATOC site that shows that the associated routing points for Bookham are Effingham Junction and Leatherhead. Armed with this information I decided that my existing season ticket was valid via Effingham Junction.

I know that this is ouside of the FGW area but was I correct in my assumption?