Hi
Yes, you can.
Any data consumed by Apple Watch Series 3 (GPS), which does not have built-in cellular capabilities, is consumed:
- Either via the paired iPhone, when your Apple Watch is connected to your iPhone via Bluetooth:
This uses your iPhone's connection to the Internet via Wi-Fi, if available, or your iPhone's cellular data connection, if Wi-Fi is not available.
- Or via a direct connection between the Apple Watch and a compatible Wi-Fi network (when the watch cannot connect to the paired iPhone via Bluetooth).
Features that are available under different circumstances are detailed here: