Your pass is good for all public transit, but not for pure tourist transports. So you can use it to travel to any town or village in Switzerland, but you cannot use it to travel on mountain railways, cable cars and busses that do not have a public transit function.
The bus from Grindelwald to Schwarzwaldalp is not a public transit service, as nobody permanently lives there. It is similar to eg. the First cabel car. There are a couple of other lines around Grindelwald that are not covered as well, for the same reason.
