Not necessarily – cell phones work off of different networks than your Portable Hotspot, meaning the two are not connecting to the same signal. This is because the Portable Hotspot connects to data networks; e.g. 2G, 3G, LTE, 4G, 5G. On the other hand, cell phones connect to cellular networks.
Since cellular networks have been around a lot longer than data networks, coverage is better because there’s more infrastructure in place (i.e. cell towers), especially in rural areas. For this reason, you might be able to make calls in a rural area but still won’t be able to access the internet.