It doesn't matter if you're in Poland, the UK, the US, Brazil, Portugal, Spain, Germany, or anywhere else. As long as you use a high-quality VPN, you can play on bet365 from anywhere in the world.
In general, there are not many countries that ban Bet365. In Europe, Bet365 is restricted to Turkey, France, Belgium, Netherlands, Portugal, Poland, and Romania. In Asia and Oceania, only the Philippines has banned this bookmaker. The most notable country that has banned Bet365 is the USA.