Quote by Dancing_Doll
I think you kind of answered your own question in your first post. She did a breezy "hey, if you're ever in my town, I'll show you around", which is how people typically leave things on vacation, while not actually meaning it if this were ever to come to fruition, and then basically put you on ignore as you sent her messages on social media and commented on her pics. She's just not interested. Whether that's because she's just not into you, or that she doesn't do long-distance, or she already has something going on at home (ie. boyfriend), it's hard to say. I would definitely leave it alone though.
Thing is - on vacation, we meet tons of different people and have different levels of interaction with them. Being friendly on vacation is not the same as being friendly at home in your own city/bar/social-scene. You mention she was in your 'group' - if that meant your tour group or it was a Contiki thing, then it practically requires you to be friendly and chill with everyone. Even on resorts - it's a bit of a cooked situation - you talk to everyone, you're friendlier than normal with total strangers because you have something in common - you're tourists, foreigners, you're in vacay-mode etc. You have to take it all with a grain of salt that they're just being 'vacation-friendly' - not 'I-want-to-date-you'-friendly.
I think you already put yourself out there, she was polite in return, but now she's no longer responding and she's likely already moved on - so I think you should too. Sorry, I know that's not the answer you wanted to hear, but you can't push something like this. If she was into you, she would have kept the convo going on social media. There's nothing you can do from across the country that's going to suddenly wow her into a long-distance relationship and honestly I think the more you keep at it, without any encouragement from her, the more off-putting it's going to be.
You know to some degree this sort of was the answer I was looking for; I think you make a very valid and perceptive point. For the most part, other than a fleeting thought during that vacation. I've really overlooked the fact that this was a vacation group so everyone was going to be at their amiable "best behavior". Thank you for the perspective and an idea with which to ground myself.