Wanted to follow up on this as I finally got it resolved and I now see GRIN in my Vite Wallet (iPhone).
After opening a ticket with support this is what happened:
In the top right corner of the app, when you open your GRIN wallet, there are 3 dots which gives you an option to "Check". You select that and it re-syncs your wallet. I had to let that run and keep that app open (I had to prevent my phone from going to sleep), until it fully syncs, this took about 15 minutes for me.
After syncing, I could see the latest "Complete" transaction for the correct amount but on the app I still couldn't see those coins as "spendable". After checking the transaction more closely, I found that it seemed to be stuck in the Vite Gateway.
As per Vite's instructions on this screen, there is an button option to "resend". After this completed (another 10 minutes of waiting), I finally saw the funds as "spendable" in the GRIN wallet.
Overall, this was one of the most frustrating experiences of any wallet I have ever used. It is slow because the node it is syncing with is somewhere in Asia (straight from the horse's mouth) and if you are in the USA, the app will feel very sluggish with every loading screen you see. I guess if or when a node is added somewhere in the states, that the app will perform better for USA users.