hide/unhide rows based on reference to cell that contains a formula result (vlookup)

Here's what I'd suggest: put a column in your lookup table to the far right of your values. Enter TRUE or FALSE for each desired state of visibility for that row. Point your lookup formula to that, then name cell O8: IsVisible. Try the following code:

Sub Hide_Unhide()
    Rows("16:17").Select
    If Application.Range("IsVisible").Value = True Then
        Selection.EntireRow.Hidden = True
    Else
        Selection.EntireRow.Hidden = False
    End If
End Sub

Note that there's a better way to do this that doesn't involve selecting the rows, but I'm having a brain freeze at the moment for the correct syntax to refer to the range object. If you know what it is, then something like:
Range("16:17").EntireRow.Hidden = FALSE

Should do the trick without having to select. I just don't remember the proper syntax...