Yes, get a good teacher.
But what is a good teacher? It depends on the student.
If you are a beginner struggling with technique and learning efficient ways to practise, you need a teacher that will fulfill these needs.
If you are and advanced student who already can play everything, you may need advice on interpretation and on things like how to project the piano sound in different concert halls with different acoustics.
So, maybe your community teacher is good - for you, at this moment in time.
Also, being a famous concert pianist is no guarantee of good teaching (only of high fees!). In fact I would stay away from teachers who are performers (controversial issue!) since most of the time they will be putting all their energies on their performing career and will have little time to devote to teaching. The only time I would consider a teacher who is a famous performer is if I want to learn about performance. If I want to learn the piano, it would be a waste of both our times.
So how do you know if your present teacher is good? Have you learned everything s/he has to teach you? If so it is time to move on, and most teachers will actually move you on when this is the case.
Also have initiative. Do not rely totally in your teacher for your piano studies. Read, listen to music, go to concerts, do research on your own (You are doing just that by joining this forum). Discuss new ideas you discover with your teacher. Does s/he already knows about them? Can she add to the knowledge you acquired through your research? If so, s/he is a good teacher and might just be waiting for you to come up with something s/he could use.
Finally, look around in this forum. There is a huge amount of information on all areas (from the best CDs to listen to and the worst to avoid to discussions on specific pieces).
Best wishes,
Bernhard.