In the scene where Teal'c and Ronin spar, the bets being placed are visibly in US, EU and Canadian currency. What isn't so clear is why currency is there at all - given that there is never shown any commerce or shops on Atlantis. There is mention of getting "paid" in a few episodes, but this is one of very few times actual currency is shown. Having been stationed in a place or two where currency was not needed, it still existed. Mostly for the weekly poker game.
Teal'c is the last member of the original SG-1 team to visit Atlantis (onscreen, at least), having not made the trip in the crossover episode The Pegasus Project (2006).
The only visit of a Jaffa to the city of Atlantis in the series. The Jaffa are the most commonly seen alien race in Stargate SG-1 (1997).
Ronon makes a comment about how Teal'c always says "Indeed". To which Teal'c quips he hadn't noticed. Ronon then later uses the word himself. It is a well-known, in universe personality quirk and this exchange was likely meant as a tongue-in-cheek nod to fans of Stargate SG-1 (1997).