Here is one campground in the Tagaytay, Batangas area. It is in Talisay, right on the  shoreline of  Lake Taal, about 15 minutes from Tagaytay. 

Taal Lake Yacht Club was set up primarily as a sailing club. However, the way it is set up, it is now considered one of the best campgrounds within 1 hour from Metro Manila, Luzon, Philippines. 
Rates are $2/day/person. It costs $3 to pitch a tent for the evening, and very large native style open cabanas surronded by flowers and soft grass are available for around $8 per day. 

 The biggest problem you will encounter if you are traveling in the Philippines is adequate bathroom facilities.  TLYC is set up as a daytrip destination from Manila. We have picky members. As a result, the central focus of the facility has to be good bathroom facilities for members and guests. Our bathrooms are good. We even have hot water if you want it. 

We do allow picnics, so we also have good washup facilities. 
If you don't want to cook your own food, we can supply adequate food if necessary, even during the week.  If you do decide to camp, the grassy lawn is nice and soft, you will be surounded by flowers, and you will have a view that absolutely can't be surpassed by anyone in the area. 

We are a preferred destination of scout troops that are preparing for "the real thing". We provide an area which is a sort of "introduction to camping" experience. We want to promote camping in the Philippines, but we recognize that many people here have never done it. We want to provide the "no risk" opportunity for people to try it with their families.

We "ease" people into it. You can bring your family, or friends, and you can enjoy sleeping under the stars in a remote area. You have the choice of trying to cook your own food if you want, and you will not have to deal with the realities of camping where there are no toilets.

We don't have rooms for rent (although some of our neighbors do) 
because we do not want to have campers kids saying "Daddy, lets move to the room with the TV". If you decide that thats what you want, no problem. move to the hotel about 200 meters down the road.  It takes 10 minutes. At least you tried camping.

Taal Lake Yacht club is located on the Northern shore of Taal Lake or Lake Taal, in the town of Talisay. It is a perfect spot for catching Banca rides to Taal Volcano, and it is only about 15 minutes by car from the Tagaytay ridge road. It is about 30 minutes from Tanauan. Go to the Taal Lake homepage for more info on location, facilities, rates, pictures, etc.