If a person is a POD on an account only, we do not need to get CIP information on them do we?

The answer to any CIP question is "Check your bank's CIP policy so see what it calls for." Your subject says POA and your question says POD.
I can answer for my bank's policy. A beneficiary would not need to have a CIP as they are not an owner/signer of the account. We do require a CIP for a Power of Attorney becuase they are a signer on the account and we do track common signers on accounts with different ownership as part of our BSA/AML compliance.

I have been trying to find information of Representative Payee accounts. I know that the Rep Payee is the only one who can do any tranactions or change anything on the account but can the person who is being represented get information about the account? We have a Rep Payee who does not want us to tell the person represented the balance in the account. Since it is their money, can't they at least know how much they have in the account, assuming they have the capacity to understand the info?

We shouldn't assume anyone's mental capacity. Someone went to the SSA and convinced them that the individual does not have the capacity to handle his/her financial affairs; therefore, we should honor the agent's authority over the account. If the individual does have the capacity to handle his/her own affairs, he/she should go to the SSA and have the rep payee removed. This happens sometimes in accident and stroke situations.

I wonder why the rep payee doesn't want the owner to know what's in the account? The owner doesn't have signing authority or access via debit or atm card. One might wonder if the funds are being utilized for the benefit of the owner.

Every situation can be so different. A quick review of account activity should help you determine how the money is being used. If I felt my customer's welfare was at risk, I might elect to report under the Elder Abuse rules.