Probably. The question is where do you want to go with it? how fast? and how much fuel do you have? how many people have to fit int? I would guess we could probably design a bus that is good for short and slow water trips – like some of the amphibious vehicles that are used for tourist tours (Duck Tours ?). Once you want to go faster or further, it’s probably not so efficient to have a floating bus. A proper boat would be better. Or an aeroplane. Or something in between? I would really like to design an Ekranoplan – a plane that flies very close to the water surface, which makes it really efficient 😉
Do you mean a bus that can go on the road and also on water? My team can’t build anything because we don’t have those skills but we’d be happy to ask passengers what they think of being on a floating bus!