It's very probably it fits. Fuji doesn't tell exactly, but it looks like the adapter plate fits on graflock mount, which is an old standard in camera industry and almost all view cameras have it.
I guess your Sinar has the so called spring back (you put film cassette behind the ground glass, which is mounted with springs).
To see the Graflock you have to remove the spring back. There are two "knobs" or pieces of metal over and under the ground glass (if in horizontal position). Push them and slide the back with ground glass a little to left or right and take away. Don't drop it!
Now you see two sliders also over and under the hole. With them you can mount many kind of equipment, the film cassette for example, and I guess the Fuji view camera adapter too.