So my question is how to delete bundle I created?
You create bundles with this console command:
php app/console generate:bundle --namespace=Test/BlogBund
I know I am late to answer this but Symfony has instructions on how to delete the bundle. This is how I delete. You can use the same instructions for other bundles you created and want to remove now.
It is basically the process you have outlined, only in somewhat different order.
If this wasn't installed using a dependency manager - that should be all.