well, it depends what you want to do, if you want to learn about benares gharana, then go to the holy city. If you want to learn tabla from anywhere else then go to Bombay. The thing is that you have many people in bombay who know about tabla from delhi, punjab, lucknow, etc, including benaras, but there still is MORE knowledge about benares tabla in benares.
Another factor you may want to consider is money. Bombay along with Madras are the two most expensive places in India. Bombay is very hard on the pocketbook. If you aren't totally set on one or the other you might want to consider Calcutta. There are many great tabla teachers there. You may have noticed that many of the most popular tabla players are from there: Tanmoy Bose, Arup Chatopadaya, Subankar Bannerji etc. Calcutta is a great city but cheap to live in and still affords one a large variety in the way of teachers. And BTW - no I am not Bengali.
Anindo and Kumare bose are also in culcutta. There are couple of more places. First in Ahmedabad GUJARAT. If you want to learne BANRAS then go to Nandan Mehta who also arranges the well know saptak.
And if you want to learn anything else i.e. Delhi,Ajarada,Punjab go to Divyang Vakil. He had three gurus and all three were best (Late AllaRakha Khan, Late Latif Ahmead Khan and Pt. Sudhir Saxena.) I learned from him and I would tell you he is one of the best teacher in the world.
You can also go to Pt. Sudhir kumar saxena in Baroda Who still teaches and who is khalifa of Ajarada Gharana and some of my friends also learn from him.