Thanks for your question!
You are correct, in this case you are free to invert the order of the words within the sentence:
"Aspetta anche lei un taxi?" and "Aspetta un taxi anche lei?" have the same meaning.
However, in the first sentence the emphasis is slightly more on the object that the subject of the sentence is waiting for (in this case the taxi - "un taxi"), while in the second sentence the emphasis is slightly more on the fact that even the subject of the sentence is waiting for a taxi, together with the speaker (in this case "anche lei"). This is because, usually, the last part of the sentence is more emphasized compared to the rest.
Hope this helps :)