Focht When Ichigo was training his reiatsu did not increase in any meaningful way.
Yes all his Bankai does is increase his speed nothing else....
Actually that statement isn't entirely accurate.
There is another Bankai that only improves the users offensive ability and nothing else.
We have also never seen Ichigo move that fast since the Byakuya fight.
How ever we do know that Ichigo's upper limit is higher then Uliquarra in his released state.
Taken what we know now Uliquarra is referring to himself in his second release state where his reiatsu would be the highest..