No, it's not. Other than the branding, the basket looks different, the bikes and the stations look different. Citi Bike Miami is Run by Decobike LLC, not Motivate, which runs New York City bike share, and they use different hardware.

Interesting. I don't really know how branding works, but it looks like Citibank, and not Motivate, owns the Citi Bike brand; Citibank also sponsored Miami. The The look of the bikes, and of the Citi Bike Miami website, are almost identical to Citi Bike New York, even though they are completely different companies.