The prize

While they were obtained in the USA, the person wearing these trophies is not. The team they were on had won for the first time in 2011 and then the second time in 2014. What city is the team from?

We're given this image:

The image itself has no useful metadata, so our best hope is to understand what's inside the picture using reverse image search. I tried using Google's and got this:

We can see similar ring posted by the account "@AlexisSambuco". While I can't find the exact post where she posted the image on her X account, I found this post. The year 2016 matched the year in her ring, and the trophy's logo also matched that found in the ring.

Here she mentioned "#f5ordie", which refers to her team. F5 is a cheerleading team. So we can conclude that she was participating in a world cheerleading championship and come out as a champion in 2016. We can confirm this by looking at Wikipedia's The Cheerleading Worlds 2016 section and found this:

Now to answer the initial question, we can look at the same Wikipedia entry for 2011 and 2014 and see which team won in both of the year.

Excluding US-based teams (as mentioned in the description), the only team that won in both year is Bangkok University, which is based in Bangkok.

Flag: flag{Bangkok}