If we own a property for the last 10 yrs since 2009, that became qualified into an opportunity ZONE, do we get to reap the tax benefits if we own it for another 10 more yrs ?

Unfortunately, under the current regulations, you can't derive any Opportunity Zone tax benefits from the property simply by holding it for another 10 years. However, should you sell the property to a development group to develop/redevelop the property, you could invest your capital gains in that project and derive the Opportunity Zone benefits in that manner. As the current property owner, you would be limited to a 19.9% interest in the new entity created to develop/redevelop the property. I hope this helps. If you have further questions, please let me know.