if you fall among the restriction regions, it will display on your screen and if you make use of a VPN, then all at your own risk, though you might enjoy gambling, but other privileges may not be granted for the cause of violation.
If a player is from a restricted region, they should not sign up even though they can bypass the restrictions by using a VPN. The reason casinos are VPN friendly because, they want to allow users to bypass possible ISP restrictions. Also, sometimes a VPN boosts your internet speed. Sometimes, VPN helps you bypass some game restrictions as well. I am not sure if this works in Spinly.
If you talk about privileges, I think they already confirmed that if you use a VPN, you cannot access the Goblet feature, which allows you to get free spins and free Satoshi. I am sure there is a reason behind it. The casino want to make sure people do not abuse these features.