For instance I have this code:
var text = new createjs.Text("Hello World", "Bold 10px Arial", "#000000");
And I want it to get turned into bitmap.
You can use the cache() method, which creates an off-screen canvas of the content.
var b = text.getBounds();
text.cache(b.x, b.y, b.width, b.height, 2);
Here is an example showing cache, as well as exporting the cache to a dataURL, and then making an image with it. http://jsfiddle.net/0wgwaLr6/
var url = text.cacheCanvas.toDataURL();
var img = document.createElement("img");
img.src = url;