You will find quite a few Filipinos around west london, near staines Ashford has a large number of Filipinos working in its Hospital.
Heathrow Airport has many working in and around it, espeically the Hotels.
One place to try is the Shops there is one in west drayton and of course many in Earls court.
In and around the hounslow areas i think Phill events sometimes happen other than the big festival in the Sumer. I think the Heathrow Bowl on the bath road has a Phill bowling league, but we have never been so i don't know much about it to tell you the truth.
Like JBT said try the local Catholic Churches.
Many Filipinos like many other people who come to the UK from abroad, may not be intrested in meeting people who are fellow country people.
I know when abroad while i will never ignore or be rude to a brit who chats to me i won't be their "Best buddy" just because they are British.
There seems to be differnt groups in the Filipino community in the local area round our way.
There are the families who have lived here for years and the children were brought up in the UK.
The workers or students just passing though.
The Nurses and their families.
The spouses.
The workers here overstaying their orignal Visa.
As you have found out people may or may not be friendly some younger ones may not even speak Tagalog or other phill languages particularly well.
My Wife has met some who tend to be quite into bragging about this and that, which thankfully is not the way either of us (Thankfully with my Bank balance)
My Wife has friends who are Filipinos she has met here, but she has just as many who are not Filipino and from orignally all over the world.
We all like to be surrounded by people who have similar backgrounds to us, but in a place like London you can meet people from every culture and country in the World who you might never meet living in Phill.