Although there are some limitations to what you can do from a console session from a mobile browser, deleting buckets is not one of them.
1. Here is a view of some test buckets:
2. Tap the three dots just like on the desktop. One of the options is to delete the bucket:
3. Select that option and it prompts you, just as it does in the desktop:
4. And the toast pop up at the bottom shows you that the bucket was deleted.