We're glad to haveyou here, @carisco.
@Rustler is correct. At the moment, there isn't an option to use a Bunddle Service Item on a time activity in QuickBooks Online (QBO). We can only add inventory, non-inventory, and service items to the Service field on single time activities.
It's a great idea to have a bundled service option when entering time activity. And so, I encourage sharing this suggestion straight to our product development team by clicking on the Gear icon and choosing Feedback. I'll make sure to do the same thing on my end.
You can also send your feature request through this link: http://feedback.qbo.intuit.com/forums/168199.
Thanks for letting us know the things that we need to add and develop in the product. I'm looking forward to see this feature soon on our next update. Stay tuned for now.