For Pixel 2 64 Gb (Verizon Version):
It supports 4G LTE on following band:
1, 12, 13, 17, 2, 20, 25, 26, 28, 29, 3, 30, 38, 4, 40, 41, 5, 66, 7, 8
For LTE, Salt is using Band 20, 3 and 7.
It also Support 3G/UMTS on following frequencies:
1700, 1900, 2100, 850 and 900
For 3G UMTS, Salt operating on 900, and 2100
Support for 2G frequencies:
1800, 1900, 850, and 900
Salt operates its 2G network on 1800 frequnecy.
So, according to those information, pixel 2 us version should also works on salt network.
You can find information on CH operator band/frequency here . It is written on german though. But you'll understand the graphic easily
The specs of the US and European Pixel 2 are exactly the same.
And does phone call work as well?
The German version should def work with Salt. What you have to realize is, however, that none of the Swiss providers support Pixels phones. Which means no WiFi calling and no VoLTE. Both can be very problematic. I personally ended up selling mine because reception at home reaches between low (Swisscom) and zero (Salt + Sunrise), so WiFi calling is essential to me. Plus Swisscom has been turning off GSM antennas here so without VoLTE I often found myself unable to place phone calls.
Overall, it doesn't make huge sense to get Pixel phones in Switzerland until Google manages to sell them through one of our carriers here.