Whatever amount of property tax paid directly to the taxing authorities or from your escorw account to taxing authorities can be entered on your tax return regardless of whether it is shown on the 1098 or not. You can enter it under Federal Taxes, Deductions and Credits, Your Home.
If it is paid out of your escrow account, you should find out from your mortgage holder why it wasn't entered on your 1098. There is a possibility it wasn't paid until the following year.