>> I've been notified that the first two days of my "Grand Train Tour" will have to be altered due to some track closures. On April 24th, my wife and I were to travel on the Goldenline from Zurich to Interlaken. Instead, we are being asked to take the Goldenline to Lucerne, then a "regular" train to Horw, then a bus to Giselle, then a train to Interlaken.
The name of the train route is the Golden Pass by the way. The town you have called Giselle is called Giswil. It will help avoid confusion if you use the correct names for places and train routes ;-)
The Golden Pass route doesn't start in Zürich, but in Luzern. From Zürich to Luzern, you just travel in a normal train.
At Luzern you transfer to another train, which will take you along the first part of the Golden Pass route, which is the sector between Luzern and Interlaken Ost.
As there is some low-season construction work taking place on a section of this railway line between 3-30 April 2018, you will transfer to a bus for a short sector. This has been planned in advance and will be well organised. Your luggage will go in the luggage compartment underneath the bus. It is nothing to worry about.
You will be back on a train at Giswil for the ascent by cogwheel up to the Brünig Pass, down the other side to Meirigen, then along the Brienzersee to Interlaken Ost.
>> On day two of our tour, instead of the Gooldenline from Interlaken to Montreux, we are being told that we will take a train from Interlaken to Zweismmen, then a different train to Chateaux D'Oex, a bus to Montboven, and then a train to Montreux.
The Golden Pass is not a train, but a route, and you will still be on this route. It is normal to change trains at Zweisimmen, even when there are no construction works. (This is necessary because of the change in gauge of the railway tracks.)
You will be taking the same trains that people on the Golden Pass route normally take, with the exception of travelling a short sector by bus to get around a construction site. I have attached a screenshot showing the sector on which you will be travelling by bus in context of the whole trip between Zweisimmen and Montreux.
Again, it has been planned in advance and will be well organised. It is nothing to be overly concerned about in terms of logistics.
If you would like to post the exact details of your trips from Zürich to Interlaken Ost, and from Interlaken Ost to Montreux, i.e. departure date and time for each day, I or others can print you an itinerary and address any other concerns you have about these train trips.