what requirements do i need to apply for a HK visa?

Saeed, your Filipino GF doesn't need apply because she enjoys 14 days free stay in HK. For you, you may try to apply from Chinese embassy in Philippines or HK Immigration Department directly. If the embassy accepts your application, you may receive your passport and visa in four or five working days. However, it takes 4 to 6 weeks if you apply from HK Immigration Department.

The required documents are: your passport, filled ID1003A form, a recent passport photo, travel itinerary in HK, round-trip air tickets and hotel booking in HK.