I think they recognize familiar surroundings more than anything else. If that includes the owner, then yes, I believe they do. My torts tend to stick their heads in when a stranger approaches; whereas, with me and my familiar call to them relaxes them and makes them want to squirm to get free. Sulcatas need routine and when something changes, it affects their behavior. This is not a scientific response...I haven't studied behaviors of tortoises, but this is based on my personal experience with my three sullies.
I agree with sibi. Now my sully knows the difference between my husband and i . She knows the difference between my husband and one of our friends. She even knows the difference in my dogs. I believe they are smarter then we give them credit for.