이 가게는 커피가 맛있다: coffee is what's (especially) good about this café. 커피는 이 가게가 맛있다: When it comes to coffee, this café is the right choice.

이 가게는 커피가 맛있다. This is the answer for the question "이 가게는 뭐가 맛있어요? What is tasty menu in this store?" Coffee is tasty above all other menu in this store(café). This store(café) is famous for tasty coffee. 커피는 이 가게가 맛있다. This is the answer for the question "커피는 어느 가게가 맛있어요? Which store has tasty coffee?" As for coffee, this store(café) has tasty coffee.

Hi there. They're interchangeable in use, so I can't tell there's any difference between those contexts. But you have to say thses sentenses when you're at the restaurant at that time.