Hi
No - Apple Watch cannot connect to a Personal Hotspot from your iPhone, but nor would there be any benefit if it could.
For Apple Watch models without the built-in cellular feature, the fullest range of features is available when your Apple Watch and the paired iPhone are connected via Bluetooth and your iPhone has access to both cellular service and the Internet (whether via either cellular data or Wi-Fi). This already gives Apple Watch access to data via your iPhone's cellular data and/or Wi-Fi connection.
You do not necessarily need to have your iPhone on or immediately around you (within arm's reach, for example) for the devices to establish and maintain their Bluetooth connection. Normal Bluetooth range is around 33 feet / 10 meters (this will vary in practice due to wireless interference).
Whenever your watch cannot connect to the iPhone via Bluetooth, it will attempt, as a fallback, to connect to a compatible Wi-Fi network.
It cannot connect to Wi-Fi when it is already connected to your iPhone via Bluetooth. Bluetooth is the most power-efficient method of connection for your devices and Apple recommends keeping it permanently enabled on your iPhone.
A compatible Wi-Fi network is an 802.11b/g/n 2.4GHz Wi-Fi network that your iPhone has connected to before whilst your Apple Watch was connected to the iPhone via Bluetooth.
Apple Watch cannot connect to public networks that require logins, subscriptions or profiles or to 5GHz Wi-Fi networks:
About Bluetooth, Wi-Fi, and cellular on your Apple Watch - Apple Support
When instead connected to Wi-Fi, the watch offers a reduced range of features. If your Apple Watch is unable to connect either via Bluetooth or Wi-Fi, it again still offers some - although fewer - features.
Features that are available in each case are detailed here:
How to use your Apple Watch without your iPhone nearby - Apple Support