can you have dual citizenship in the U.S. and Phillipines?

I think that if your father was (and/or still is) a US citizen, then you are also a US citizen no matter where you were born. It should be rather easy to get an american passport in the US embassy or consulate in the phillipines for you. As for your mother, I believe that she has to apply for a US visa or "green card" based on her marriage to your father who was/is a US citizen, or thru your US citizenship if you are over 21 years old.