The idea of go-to combos doesn't really fit the playstyle of G&W like it can for other characters, where literally everything they do has a name of some sort. At least in my eyes, anyways.
That doesn't mean he isn't a combo oriented character, though. G&W combos are extremely diverse thanks to his Up-B, and as such feel rather free form. Such combo fluidity stems from how many different uses all of his moves have, and the role they play in keeping the combo going. His combos aren't always the same due to stage layout, opponent's character, and of course the incredible mix-up option that is Judge. Even when the stage and opponent remain the same, specific combos still can't be relied on due to how weird it is to DI his throw, since they all look the same. Bacon trajectories are pseudo-random, but recognizing how you can use every last scrap of meat to start a combo is vital to keeping the opponent dazed, tumbling, and utterly confused.
Good luck wavelanding Up-Air. It has a separate attack for when G&W hits the ground that it's always going to use regardless of how you L-cancel it, so you'll need to time both puffs perfectly so that you have enough frames to waveland with. Up-Air's use as an approach is limited to when the opponent is on a soft platform above you, and is otherwise used to extend a combo or punish an opponent's whiffed move from above into a F-Air or N-Air. Personally I think panslam, B-Air, F-Air flub, D-Air and D-Tilt are much safer to use and offer far more reliable results. If D-Tilt will send too far, use D-Air. If that still sends too far then B-Air will fit pretty much everything else, with the small gaps being filled by F-Air flub and panslam.
I suppose you could try using it when you're sure that some bacon is going to end up stunning, but that really doesn't accomplish anything that a grab couldn't already do better. Using it to mix stuff up a little is always good, but still not usually the best option. Besides, if you really wanted to mix stuff up a little (or a lot) you'd just whack 'em with Judge.