The main thing is ask your son what he wants to do first. He might not like bowling and you don't want to schedule a bowling party if that is not what he wants.
I have done a Great America Party. Luckily all the kids had their season passes but one. I made all the kids stay together and they did not roam off on their own.
I also did a slumber party at the Embassy Suites in Milpitas. I walked across the street and they went roller skating and when they were done they went swimming at the hotel. The hotel also had free drinks and snacks so I did not have to provide snacks and I brought a cake. In the morning the hotel provided breakfast. The bad thing about that was my child could only invite 3 friends because the hotel room accomodated 5 people unless you buy to rooms and a adult has to be in both rooms. Sorry there are no adjoining rooms at that particular hotel. I also had a cottage room at the Sheraton in Milpitas that was nice the pool was outdoors and not indoors like the Embassy, but I had buy food for breakfast.