I guess it was the first time that I've translated an SAP report after releasing the code changes to the Q system. But much to my surprise, I wasn't prompted for a transport request when I maintained the translations.
There's a very good article that explains how to transport the translations using transaction SLXT, however what I was really after was how to add those texts to the transport request manually.
So if you're looking to transport the translations of report ZEXAMPLE, simply add the following objects to your existing transport request:
LANG REPS ZEXAMPLE
LANG REPT ZEXAMPLE
In column Language, choose the target language.