I had RNY, not VSG, but it's similar. Your volume will be unrealistically restricted for the first few months or a year, but after that, not really. Although I eat much less than I did pre-surgery, no one would be able to tell anymore that I had bariatric surgery. I eat like my never-been-obese women friends do who are "watching their weight". At restaurants I'll usually order an appetizer and eat that - or else order an entree and take half of it home.
no I could never eat half a large pizza again at one sitting like I could pre-surgery, but I can eat 1-2 pieces. But 1-2 pieces is what my mother eats - and most of my skinny friends.
so to answer your question - yes, of course you'll be able to eat at weddings and when traveling abroad. You won't be stuck forever eating 1/2 C of food or 600 calories. But you'll be eating much smaller portions than what you probably atepre-surgery (or you should be eating much smaller portions - unfortunately, regain is real!! Luckily, it's easier to eat small portions and be satisfied with that after surgery)