The laws of precedence
Wheat or spelt mixed with another bracha: If its made of wheat or spelt it has precedence over any other brocha even if the other food is more desirable, other than hamotzi. (סידור הל‘ י‘)
Barley, oats or rye mixed with another bracha: Mezonos of barley, oats, or rye has the same laws as does wheat and spelt with exception of when they are together with olives and the olives are equally or more desirable, in which case the olives receive precedence.( (סידור הל‘ יא‘
Mixtures of different types of Mezonos: If both mezonos are from the ז‘ מינים and they are both equally desirable, then the mezonos of wheat comes first. If the mezonos of barley is more desirable then it precedes. If all types of grain are equally desirable then the order is 1) wheat, 2) barley, 3) spelt, 4) rye, and 5) oats. (Badei Hashulchan 54/6) A mezonos food which can become hamotzi if one eats it as a meal has precedence to a mezonos food which is cooked in water and can never become hamotzi. (i.e. spaghetti and a cookie, the cookie comes first) (Badei Hashulchan 54/6)
 However wine has precedence over Mezonos of spelt, rye, and oats. So is implied from Admur 10/13-14 which only mentions barley and wheat by mezonos that has precedence over wine, and is as well implied from the next Halacha in which Admur emphasizes that Hamotzi of all 5 grains has precedence to wine. Now if it was already established in the previous Halacha that even Mezonos of the 5 grains has precedence to wine, then certainly Hamoitzi would have precedence and thus adding wine to the next Halacha would be superfluous. Hence one must conclude that wine has precedence to all grains which are not mentioned explicitly in the verse, which are spelt, rye and oats. The Peri Megadim A”A 211/7-8 rules similarly in the Magen Avraham that spelt, rye and oats do not precede wine, and so rules Birchas Habayis 13/9.
Other opinions: The Rama 211/4, as explained in Mishneh Berurah there, clearly rules that all 5 grains have precedence to wine even if they are Mezonos.
 Siddur 10/13-14