Access rescrictions

Hello,

I'm looking for an solution to restrict the access to show an part of an Table only:
In an customer-database it should be possible to list the bills of an certain customer,
but it should be restricted to generate/summarize a list of all bills.

"SELECT * FROM Bills"  should be restricted
"SELECT * FROM Bills WHERE CustomerID=?" should be allowed for any CustomerID.

Is there an solution to this problem in PostgreSQL?

Elmar