It works fine but you have a few issues with your example.
First, your checkbox has an id of #showAll
when it should be simply showAll
.
Second, according to the jQuery API, the tooltip open method only works on non-delegated elements.
Programmatically open a tooltip. This is only intended to be called for non-delegated tooltips.
So instead of binding the tooltips to the document, bind them to your anchors.
Here's a jsFiddle example that shows all the tooltips when the checkbox is checked.