I am HIB visa holder and planning to buy a primary house in Florida. Should I buy the house in my name alone to get Tax benefit or can I buy it jointly with my wife and still get Tax benefit as I am the only earning member of the family. My wife does not work .

How much tax benefit will I get if I buy a house.

Both names on the deed or not doesn't affect your taxes. You file a joint return with your wife and that in itself is a tax advantage, since she doesn't work (and I presume has no unearned income). You can take out the mortgage in just your name if you want, so that the bank only asks for financials on you.

I can't answer the question about your tax deductions on H1B.
In general, a mortgage is a very good deduction, especially since it's almost all interest at first, and that's what you are deducting. Paying cash for a house gets you nothing except the property tax deduction.