Does the rule of eker and tafall apply to a fruit salad with fruits and vegtables when their was grapes and other fruits and vegtables inside? Do you have to make a haetz because grapes are one of the shivah minim or not?
7 minnim wouldn't matter. The only time the nature of the food will affect the ikkar/tafel status is by the 5 minim which, if significant, will take on the status of an ikar (if another food is your subjective ikar, you may now have 2 ikarim).
Additionally, some say that ikar/tofel is the reasoning behind bread/wine exempting other food/drinks.