Product Types are set while adding Products or Categories via the dropdown, just before you hit: New Product or New Category ...
The products_type = 4 is a handy one to use as it matches everything about the regular Products except it is using the document_products gang of files in the Catalog and Admin to manage these products ...
You could clone the document_products ... and I pick this one just because the variables and constants for it would be easy to follow ... and make a products_type such as products_wine or something similar ...
You'd then use this products_type which, more than likely, would become products_type 6 as your "flag" for wine and be able to control that product_type ...
Or, you can add on the products table a new field ... such as products_is_wine ... and follow one of the similar fields in the /admin to customize the code to allow for this new field ...
This can then be used for your test of what's in the cart ...
The "test" is running the function in_cart_check to see if there is one or more "wine" products in the cart ... if so, you can then customize the shipping modules to act according to the rules you need ... such as only show if no wine is in the cart, unless it is the Store Pickup ...
The Shipping modules each have a setting similar to this, taken from the item.php Shipping Module:
// disable only when entire cart is free shipping
if (zen_get_shipping_enabled($this->code)) {
$this->enabled = ((MODULE_SHIPPING_ITEM_STATUS == 'True') ? true : false);
}
This is testing the cart for if the shipping should be free based on the function zen_get_shipping_enabled ...
What that does is test for various conditions for when shipping should be Free and only show the Free Shipping (freeshipper) Shipping Module and turn off or hide the other Shipping Modules ... even though you have them installed in the Admin ...
At the same time, if Shipping is not Free ... then it turns off or hides the Free Shipping (freeshipper) Shipping Module based on the opposit conditions so it will not show when the other Shipping Modules show ...