Now if you shout ‘Hey Siri!’ at your retail business iPad or iPhone Spotify will obey your command. You still need permission to play.
To avoid infringement, you still need a music licence when you have Spotify playing in your shop, OneMusic Australia is clear about that. The Spotify company has paid for royalties for personal/home use but has not paid royalties for business use and this must be paid by you.
Check the terms and conditions of your Spotify agreement. There is important information in there about using the service beyond personal/home use.