You will be given two lounge invitations. Both will be issued in MNL. One will be for MNL and the other will be for HKG. The HKG one will state only for the Business Class lounge. Normally you are entitled to use the lounge based on your class of service irrespective of the ticket you hold. However, you MAY show the lounge agent your original ticket coupon. If it states that you are indeed on a F class ticket, they *may* let you into the F class lounge.. but then again, they may not. So be prepared on that.
How long is your transit anyway?