Hi there @tropiustodd , welcome to the forum!
I sometimes make single Pokémon lists across all languages and sets for other collectors. Since Tropius doesn’t have that many variations, I just made one for you. There are a total of 120 unique Tropius TCG cards across all languages, and I was only able to find one card featuring Tropius in its artwork (which was already mentioned by you, the Japanese 227/SM-P Pikachu promo).
Btw, excluding Reverse Holos there are actually fourEDIT: Never mind, just two… Holofoil Tropius variations. The Japanese Clash of the Blue Sky (014/082) is Holofoil, which is two variations (both 1st and unlimited edition). And the English Plasma Blast (5/101) Tropius is also available as Crosshatch Holofoil with a National Championship 2013-2014 stamp (and an additional STAFF stamp variation). Still a bit lackluster indeed, but at least it still has a lot more variations than Bonsley or Mantyke for example. 
EDIT: Scratch those English ones… They are Crosshatch Reverse Holos… 
My bad.
Anyway, welcome to the forum! And good luck with your collection goals!
Greetz,
Quuador