Make sure you do the following:
1. Did you post a review for the client? You must post a review for the client before their review will show up on your profile. You can review the client by going to My Jobs -> Contracts. Find the contract you completed with the client. Then open the Terms and Settings tab. There should be a link in there to begin the review process.
2. After your complete the review, you'll still need to wait for a while before the system refreshes your profile with the review. I'm not sure exactly how long it takes or what triggers the refresh, but I would give it until the next billing cycle (week). That seems to be when the profiles refresh with new earnings and such.
If the review still doesn't show up after that, contact Upwork and they can manually refresh the profile for you.