You can use Hotspot and Web filter together.
I just tested and there are working as expected. Once the device is logged and connected to the hotspot, you won't reach the login landing page. By default, RUT devices has the IP 220.127.116.11 to logout, you'll reach the logout page and set another IP.
Whitelist in hotspot can be also setted in the Walled Garden, so the devices will connect to these websites even without doing a login in your hotspot.