When you purchase a theme from ThemeForest that bundles WPBakery Page Builder, Slider Revolution or any other Premium plugins, you are free to use these Premium plugins with the theme.
However, your theme purchase does not give you individual Premium plugins licenses that allow you to activate or download these plugins as you wish. Activation Premium plugins doesn’t mean the plugin will not work but only that you cannot received direct updates. Please don’t worry if you see warning messages about the plugin license activation.
Also, the premium templates in sliders isn’t a part of the bundled license, it’s only an extra pack so the plugins author can get more direct sales for the plugin (not a bundled license).