It seems me that those are both the same thing. Is there any reason to maintain them as separate tags, or should we make one the synonym of the other and if so, which should be the master?
It seems to me that a question about the structure of noun phrases for example, would come under syntactic analysis, but not sentence structure. Therefore, if the consensus is that these two should be merged, syntactic analysis should be the main tag, and sentence structure the synonym. However, I'm not sure that we definitely need to merge these two tags.