Sort:  

is Bitcoin consider legal by Administration?

Yes Bitcoin is legal. There are some regulations if you are starting an exchange. I would say take a look at https://coins.ph/

There a several articles online that more detailed info.
https://bitpinas.com/cryptocurrency/is-bitcoin-legal-in-the-philippines/

https://www.coindesk.com/philippines-just-released-new-rules-bitcoin-exchanges/