No difference between laptop or cellphone.
As for tracking - what exactly do you mean by that? What are you doing when using the Wifi? How do you distinguish between tracking the person and tracking the device?
In general, using public Wifi bears a (much) highr risk of being monitored than using a private Wifi. First question, for example, would be: how (and why) sure are ou about which Wifi you are actually connected to? A Wifi server, incuding batteries, fits into a cigarette packet (or, with a bit more effort, an Altoids box). Any of the cellphones of any of the people around you could be the server you just logged in to, and listenening in on anything you transmit.