It can be argued that there is a Matter of Spain though it falls out of the three great matters established by Jean Bodel in the second half of the 12th century. This is what the man says:

"Ne sont que iij matières à nul homme atandant, De France et de Bretaigne, et de Rome la grant."

Translation: There are but three matters that no man should ignore, of France, of Brittany, and of Rome the great.

This classification is quite willingly limited, as we have to take into account that this is a Frenchman speaking of what a French cultivated man should know. It does not mean per se that there are no other matters, but that these three are the most relevant, or the ones that should be widely known.

What can be considered the Matter of Spain was at that point only in its cradle, with Chansons de geste (cantares, as we call them in Spanish) starting to develop around that time. There are some considerations to be made about why such a late development in comparison to the Matters of France, Brittany, and Rome.

The Christian kingdoms were at that point still relatively early in the "reconquista". Toledo had been already retaken by that point, but in the second half of the 12th century came an invasion that threatened to undo everything: the almohads. And from the fights against them emerged a hero that would become the stuff of legends, chansons, and histories: Ruy Díaz, more commonly known as El Cid Campeador, a nobleman from Castile who carved a fiefdom for himself in the rich Valencia.

The cycle of El Cid started to develop in the 13th century (Cantar de Mío Çid) from the Historia Roderici, the Carmen Campidoctoris, and the many popular accounts and songs of the many feats he performed or was said to have performed. This cycle even arrived to the Spanish Golden Age, with many authors writing about different aspects of his life, like Guillén de Castro with his "Mocedades del Cid".

Another cycle from Spain is the story of Bernardo del Carpio, which is tied to the Matter of France. Bernardo del Carpio is a mythical (or maybe semi-historical) character from the late 8th and early 9th centuries who the legends and chansons said he took part in the defeat of Charlemagne's forces at Roncevaux and who allegedly also fought the Saracens. Many stories and poems were written about him, and we can be sure that by the late 14th century there was a chanson about him that was popular, as that fact is commented by chancellor Pero López de Ayala, the great Castilian chronicler of the late 14th and early 15th centuries. Bernardo's stories also spun off a substantial number of popular songs and poems (romances), duly compilated in the Romancero General (Antwerp, Maarten Nuyts, 1550).

The other big cycle is the one on the Seven Infantes of Lara. These seven infantes are also semi-historical and semi-mythical, and presumably from the late 10th and early 11th century, in the times of Almanzor, though the chronology can vary here and there. The span of these legends is a tad less vast than those of El Cid or Bernardo del Carpio, but still noticeable. It did get even to the Spanish Golden Age, just like El Cid's cycle and Bernardo's cycle.

So, going back to your question, there was a Matter of Spain, but as it did not have the development the Matters of Brittany, Rome, and France by the time Bodel made his remarks, it is often glossed over. It also does not have an overarching unity, unlike the Matters of France and Brittany, and it is not rooted in Classical Antiquity.