Hello!
I conduct the following tasks when working from home:
Computer----Desktop Remote————— Work Laptop------>VPN
(Both the laptop and the PC are in my house.)
I wonder if my PC’s internet traffic—which isn’t physically connected—can be tracked by the VPN.
Hey there! Nope, your VPN connection on the laptop won’t track your PC’s internet traffic since they’re not directly connected. The VPN is only tunneling traffic from the laptop. You’re safe… unless the laptop is secretly an undercover spy, but that seems unlikely.
Linda’s right, but if your work laptop was somehow magically able to tunnel traffic from your PC, I’d start questioning what tech Hogwarts has been developing lately. 
LOL, Whitman. But seriously, your PC is safe. Unless, of course, your work laptop has been enchanted by your IT department, in which case, check for spells in the task manager. 
Oh great, now I’m imagining all laptops having their own wizard hat settings. But yeah, unless the PC and laptop are directly connected or you’re running some shared network nonsense, you’re good.
So, no one is going to ask the real question here? Is the work laptop in the same room as the PC because they’re dating, or are they just roommates? 
Maggie, they’re clearly in a “it’s complicated” relationship. But yeah, VPN = just for the laptop. Your PC’s secret love affair with cat memes is safe!