Probably not, or maybe.
The toning or unstable shoes are shoes that are deliberately design to make the muscles work harder and are supposed to give the body an extra workout. These shoes have a checkered history with dubious claims, legal action and settlements with regulatory bodies. Despite that they do have their uses and can be used to change the gait in those with postural problems as the shoes change the gait. They can also be useful for people with a hallux rigidus or a painful osteoarthritis of the big toe joint. The rocker action of the shoes does restrict movement at the big toe joint means that these types of toning shoes can often be prescribed by clinicians for these types of conditions.
So, can they help bunions? Firstly they are shoe of normal width and are not necessarily wide fitting, so they might not be helpful to bunions unless the forefoot of the shoes are wider. If they are not, this may make them uncomfortable to wear. If there is pain in the bunion when walking, especially when the big to joint is extending, then these toning shoes might be helpful as they do restrict that motion. You really need to get the advice of a health professional as to if this is the case in your situation and if these shoes can help.
What if you want to use the toning shoes for reasons other than the bunions? Bunions are no reason not to use these types of shoes. You just need to be careful that they fit correctly in the forefoot and do not cause any discomfort problems in that area. Like anyone using toning shoes, you do need a period of time to get used to them and use them for short periods of time initially. gradually increasing the amount of time that you use them