You should always look for your answer before asking your question. I read this on an official page in the support section. Looked for it couldnt find it again. Mw3 And Bo2 clan information with be two separate entities. Meaning under BO2 your clan will be reset while your Mw3 clan info will remain. There are if you haven't noticed more clan ops for Mw3 even after BO2 comes out. So you will still be able to level your Mw3 part of the clan up.
I found it!!!
Yes, your current Call of Duty Elite clan for Call of Duty: Modern Warfare 3 will transfer over for Call of Duty: Black Ops II. However, your Call of Duty Elite clan level for Call of Duty: Black Ops II will be reset, as it is separate from your Call of Duty Elite clan level for Call of Duty: Modern Warfare 3. Additional details regarding leveling up your Call of Duty Elite clan for Call of Duty: Black Ops II will be released at a later date.
This is listed under the Ending Call of Duty ELITE Premium Memberships