At first glance, Zidane x Garnet look like Cloud x Tifa. But Garnet also happens to be the magic user/summoner, like Aerith. There really isn't a lot of similarities between either couple, but a few things caught my attention.
We all know how Aerith asked Cloud to be her bodyguard. In FFIX, when Zidane and Tantalus's mission is to kidnapped Garnet. However, Garnet asks Zidane to kidnap her, instead of the other way around. The play "I Want to Be Your Canary" in FFIX, is similar to the play in FFVII, "LOVELESS." In which, both plays are intended for Zidane/Garnet and Cloud/Aerith. Another cute aspect I noticed was that Aerith is very flirty with Cloud, as Zidane is to Garnet.