Dexcom G6 FitBit Versa/Ionic direct data link

I have read that the Dexcom G6 will send data direct to a Fitbit Versa/Ionic so it doesn’t have to route through a phone like an iWatch would. This seems to be a great advantage for sports where you might be able to wear a fitbit but can’t carry your phone around. (or even in the pool)

Here is my question to anyone familiar with the topic. The Dexcom G6 lets you pair with your iPhone AND with the Dexcom Reader device BUT you can’t pair with 2 iphones at the same time. So, my question is, if you opt to have the Dexcom send data directly to a Fitbit smart watch, does that mean you can’t have the transmitter paired with your iphone? or is it a BONUS device, in addition to the iPhone and the Dexcom Reader?