Very good name. Ignore all of the comments comparing the name to English words such as rotten and rot, the name does not sound like that. A boy I knew pronounced his name as "Row-tehm" which does not even sound remotely close to said English words.
It's a nice name if you can look past the fact that it sounds soooo similar to rotten which isn't exactly a good association. But it's err.. Kreatyve and original?
The meaning is not "to bind", but "retama", genus of flowering bushes that found natively in North Africa, the Levant and some parts of southern Europe.