I would not try to do two of any of those attractions in the same day. I think you'd miss too much because you'd be rushing around trying to see as much as you can in a very short time. I suppose if you really HAD to do it, you could go to the Zoo first thing in the morning and do just the bus tour, and then head up to the WAP and do the savanna tram tour there, then spend the rest of your day wandering some of the rest of the park. By the time you drive, park, and walk from your car to the entrance it will be at least an hour between the two parks. If I had to choose between the Zoo and the WAP I would choose the Zoo - it's got the pandas, koalas, polar bears, the new Elephant Odyssey, and a couple of interesting animal behavior shows.