There are certainly people who do Connect Hue bulbs directly to the smart things hub, but the only officially supported method is using the hue bridge, and there are some problems you can run into.
https://support.smartthings.com/hc/en-us/articles/200848024-How-to-connect-Philips-Hue-devices
If you want to consider using the bulb without the hue bridge , read the following thread first:
I see that there’s a device type for “Zigbee Hue Bulb” and that a new single Hue bulb is detected by the ST hub as this when I search for new devices. It seems to pair, but doesn’t respond to commands. Is there support coming for talking to Hue bulbs over ZLL without the hub? I picked up this bulb for $20 from a company that was getting rid of some of their tradeshow/marketing displays and had a spare new-in-box Hue bulb. Not the end of the world if I need to get a starter pack to put it to use, but if support is coming soon (or ever) I may hold off. Any word? Maybe something in beta (I’ll be a guinea pig if you need testers)?