Yes, vintage cars are subject to the same regulations as modern vehicles up to 3.5 tonnes.
If they use the Swiss motorway, they require a vignette.
Any vehicles and trailers over 3.5 tonnes are subject to the LSVA / PSVA.
Related articles:
Where can I buy the Swiss motorway vignette?
How much does the Swiss Motorway Vignette cost?
Are shorter term Swiss motorway vignettes available (daily/weekly/monthy)?