The simplest way to check this sort of thing (in my opinion) is to look at Cholsey to Surbiton (a relevant station in zone 6 on the line of route you want to take) on the NRES planner. This shows journeys both via Reading, Virginia Water and Weybridge; and also via Reading and Basingstoke, at the same ticket price.
That would give me enough evidence to say it was OK, without delving into the routeing guide.