You've understood the correct meaning in this context, and you're right that it's poetic licence. "pole" rhymes with "control" in the lyrics. I've not heard the phrase used in ordinary life. "top of the tree", "top of the pile" are similar phrases I have heard which contain "top of".

The lyric is actually 'top of the poll' i.e. 'Poll' as in survey of public opinion, not 'pole' as in great big long metal thing. The meaning is not so much that his fame is increasing but that his popularity with the public is increasing. If you are 'top of the polls' then you have a good approval rating with the public. There is the similar phrase 'top of the tree' which means that someone has reached the top of their profession or area.