No reward yet, my steps for linking:
Logged into account link page on Warframe website
Clicked "use another Apple ID" since doing the ID right away didn't work; login worked fine on the new tab using normal Apple ID info
Showed the confirmation page to link the accounts, was very clear PC was main and iOS would be collapsed into it. Everything connected!
Clicked to log in on iOS app, which seemed to work fine, but then it asked for an alias. I typed in the same alias I use on PC account.
After some login screen buffering, it showed my account and let me hop right into my orbiter on normal account
Other than not getting the reward, it seemed to work smoothly doing the steps above. Will patiently await, but for now - thanks DE!!