I'm not well versed in PH politics but I do agree that China needs to be able to win the hearts of the elites within a country if they want any successful long-term relations with a country.
One of the things that Western news talks about is the political corruption and bribery that comes with BRI, but I think this might be intentional as you can see with countries China heavily invested in has elites giving her the good word, like Egypt and Africa. So I think China could expand their influence in not only PH but also in ASEAN, through BRI projects and other financial assistance. But in the case of PH, it may take a while to uproot the influence US has over the elites. As long as China keeps trying and putting resources into it, they may succeed to a certain degree and gain a chance to further consolidate gains in the future.
Also, as you pointed out:
This is one of many opportunities China should take and more will come to the future as
EROEI of the current oil and gas well falls, and sweet spots become more and more scarce. Nations in the future will fight over these resources, forming limited alliance or cooperation to make it worth for both parties, or to drive out the competition. Taking this opportunity however, requires that China maintain their naval influence over that region, and keep the pressure just enough that they don't look to US for help but make the option of working with them more lucrative and attractive than working with US.
Yup, I was born and have lived here for a long time, but I don't consider myself a Filipino, especially when my Filipino is terrible and being oblivious to what is happening within this country