Yes it is possible (BPI, BDO or MegaLink) but you have to have a GCash Account connected to a mobile number (of course) and you have registered under "MY Account" GLOBE.
Also, make sure that you BPI or BDO or MegaLink Account is/are registered for mobile banking
Learn how to enroll your GCash to BPI Express Mobile
Step 1Enroll your BPI AccountSimply text ENROLL<space>ACCOUNT#<space>JOINT ACCOUNT INDICATOR and send to 2274.Registration is FREE, but prepaid subscribers need to have at least PHP 1.00 load.
Visit any BPI ATMInsert your ATM card and key-in your PIN. Select Special Services > Activate Enrollment > EConnect - SMS Enrollment to complete your enrollment.You will receive your 6-digit BPI Mobile PIN within 24 hours.
Change your BPI Mobile PIN
For your security and convenience, change your BPI Mobile PIN now. Dial *119# > BPI > Account Maintenance > Change MPIN > Enter details as required.
You may call the BPI Hotline at 89-100 for questions on your BPI Express Mobile account and the GCash Hotline at 2882 for any GCash inquiry
Then you can now
Transfer funds to your GCash wallet from your Bank Account
using "My Account" and BPI