If you use your phone as personal hotspot and connect to VPN on your laptop (not phone), then browsing activities performed on the phone can be viewed by your carrier (while traffic from your computer will go through a VPN server).
This includes, but not limits to: full URLs of pages you visit (for HTTP sites only) or website’s IP address (for both HTTP and HTTPS sites), your location (based of carrier’s data), browser’s user agent, and much more.
If you connect to VPN on your phone, those same things are available to your VPN provider (e.g., your company).