Right now Siri says "You don't have any reminders," whew. But then Google Tasks tells me I have at least 9 things to do today. Whoops.
Yes, I know this question has been asked before, but the answer is a moving target as integration with outside services gets tighter. And yes, I know there are third party services IFTTT, for instance. And I know there are other apps that provide reminder/task integration with Google Tasks (I use GoTasks).
But…
I like Google Tasks because it is integrated with my GCal. And it would be swell to have Reminders integration. Then Siri could schedule and access my tasks.
What is the current likelihood I will be able to easily integrate iOS Reminders with Google Tasks?
I suggest leaving this question open, to reflect the moving state of this integration. I will check this as answered if someone offers native or relatively simple integration.
Update: Awesome, I just got the "Popular question badge" because this question has has more than 1000 views. But uh, not awesome: Not one upvote? And only one semi-sorta-answer? Hmm.
Best Answer
You can use a combination of IFTTT and Zapier.
Bizarrely IFTTT supports iOS reminders but not Google Tasks (https://ifttt.com/ios_reminders).
Zapier supports google tasks but NOT iOS reminders (https://zapier.com/app/explore)
The trick is to trigger from IFTTT and send an email to Zapier which triggers on the email and then updates Google Tasks. I've tested it and it works. The biggest challenge is when you have multiple reminders lists. In this case I have not found a good way to dynamically select the google task list from Zapier as it keys off of task list id and not task list name. I suggest making a separate Zap for each reminder list.
Finally this doesn't solve the problem of doing the initial sync. You can use the gtasks app for this.