All the plugins listed in the integrations section are not included in YITH WooCommerce Coupon Email System.
In order to take advantage of a specific integration, you need to purchase and activate the premium version of the related plugin.
YITH Coupon Email System and YITH Multi Vendor are 100% integrated. The Integration between YITH WooCommerce Multi Vendor and YITH WooCommerce Coupon Email System allows vendors to set up an automatic sending of customized coupons when certain conditions happen.
From the administration side, you can select to make certain events available to vendors in YIT Plugins -> Coupon Email System -> Vendor Settings.
Vendors will have a “Coupon Email System” section where they can set up coupons based on the events selected by the site administrator.
Coupons sent by a vendor can be used only for those products related to him/her.
For all information about YITH WooCommerce Multi Vendor plugin, please have a look at the documentation.