I thought is was a deliberate pun. Maybe something along the lines of "The city of Paris is trying to develop parkour and capitalize on it", with the bet being used in a business sense. Turned out there is nothing looking like a bet in the article and it is just a poor choice of words instead.

"Paris sportif" really means "sporty Paris". "Sports betting" would translate to "Paris sportifs" (plural) or "Pari sportif" (singular). It is quite subtle, that's why I expected it to be a clever pun.

It means both, depending on you deciding it's paris (bet) or Paris (the city). It did lead me to expect something else from the article though - I was expecting more gambling, so I guess you're right about it being slightly misleading.

IIUC if it meant "bet", it should be "paris sportifs" (according the plural).