Just applied for this today, both a Visa and an MC app. As far as I could tell, most links to the app (including the link in post 541 here) were dead and re-directed to Citi's main CC page. I was lucky to find in my browser history a backdoor into the application page, having opened it a few weeks ago.
I am providing that link, which is working at least for now. There's no language about the 50k points, but after I applied I had to call for final approval, and I asked the representative to confirm the 50k bonus, and she did (same 50k bonus after spending 2.5k in 3 months).