Hello,
Would the Smartthings hub act as a Zigbee hub for bulbs like below, so I can operate them using google home without buying a separate hub?
Thanks
Yes, they work with SmartThings without a hub
I’d suggest also looking at the IKEA Tradfri zigbee bulbs. They are even less expensive than the Innr line and come in more shapes and sizes, are brighter than most competitors, and happen to be very good zigbee repeaters, including for the usually finicky Xioami sensors. The only catch is that you can only buy them directly from IKEA, and often only in store. They will say they need the gateway, but you can use either the smartthings hub or hue bridge instead.
The Tradfri smart bulbs and pocket sockets work with smartthings. Handheld buttons and remotes do not.
At £9 for a 1000 lm E27 white smart bulb, or £9 for a plug-in pocket socket which is a good zigbee repeater, it’s hard to best the IKEA price. 
https://www.ikea.com/gb/en/products/lighting/smart-lighting/
I don’t remember if IKEA has a bayonet base model, but they should work fine with a socket adapter and those are typically less than £1.50 each.
As far as brightness goes, most smart bulbs, including the Innr, top out at 800 lm. The similar IKEA model goes to 1000. 
Sorry for dredging an old thread. Can anyone tell me if the innr bulbs help extend the zigbee mesh.
After a lot of aggravation trying to get IKEA and Innr bulbs to connect to my ST hub I eventually found an article that says connecting bulbs to the ST hub is not supported (although there are reports of success)
I had endless issues with lights being found (some of them), losing them, suddenly appearing offline, turning on/off at random… Added a Hue Bridge. All fixed.
Turns out that although most smart bulbs will say “works with SmartThings” as far a I see, it’s not supported and you can waste hours trying. Add a Hue bridge and it all worked perfectly immediately.