Hi,
There are a lot of different approaches to removing glue blocks from
the bottoms of bowls.
personally i use hot melt glue when using a glue block but i have also
tried out using different wood glues too. i suggest that you part on
the glue line at a fairly low speed down to a tennon of around 1 1/2"
inches ( depending on how large the bowl is), removing a slight bit of
the bottom of the bowl, and then cut through the rest of it wit a thin
bladed saw( hacksaw or similar) and then sand using a circular sanding
disc on your lathe or hand sand it, and finish it using whatever oil
or finish you have on the rest of the bowl.

Hope this made sense.

John