Yes, you can install the Hue Bridge integration app on as many Hubitat hubs as you want. I wouldn't recommend doing it with polling enabled on a ton of hubs since that's likely to create more traffic and be more taxing on the Hue Bridge than it needs to be, but there is nothing stopping you from authorizing as many third-party apps (that's all Hubitat's integration is--there are lots of them for Hue on various platforms) as the Bridge can handle, which I'm sure has a theoretical limit in its database somewhere but nothing here from a practical perspective.
Or if you were asking about multiple Hue Bridges: Hubitat's stock Hue Bridge integration can (as of an update made a while back) handle multiple Hue Bridges--or, to be clear, you install an additional Hue Bridge integration app for each Bridge and choose the one you want as you finish installing the app. (And not to plug myself, but my CoCoHue app can also handle multiple Bridges--one child app per Bridge.)
Both ways work. 
I've also experimented with a Hubitat hub dedicated entirely to smart bulbs as an alternative to a Hue Bridge, but I eventually moved back to Hue. Even with only bulbs all on their own network, some Zigbee commands seem to get lost sometimes in my experience (from a user perspective, not something I saw via sniffing)--e.g., an on() would get there, but a setLevel might have to be sent twice for it to actually work. The fact that my Cree bulbs still managed to fall off on this Hubitat despite never having problems on Hue also played a part in this decision.
