cover charge

from The American Heritage® Dictionary of the English Language, 5th Edition.

• noun A fixed amount paid when arriving or added to the bill at a nightclub or restaurant for entertainment or services.

from Wiktionary, Creative Commons Attribution/Share-Alike License.

• noun An amount of money to be paid for entering a bar or restaurant where entertainment is provided.
• noun An amount of money added to a restaurant bill in lieu of tips, and to pay for uncharged items such as bread and water.

from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.

• noun a fixed charge by a restaurant or nightclub over and above the charge for food and drink