RolandP
Hello @hobbs
There is a follow-up regarding your question. I contacted the Grindelwald bus company to clarify the validity. The customer service replied that their website is outdated and will soon be updated.
Bus lines 121, 122, and 123 are free with the Jungfraupass. The touristic lines, for example to Grosse Scheidegg, are payable.
Best regards,
Roland