Did Bourbaki write a text on algebraic geometry? Certainly Bourbaki never wrote an introduction to algebraic geometry: we would have heard about it, right?
 A: Wrong!
Here is Bourbaki document on algebraic geometry, taken from the now available Master's Archives: click on Autres rédactions, then on Chap.I Théorie globale élémentaire (91 p.) 
This preliminary draft was  apparently written (according to a penciled annotation on the first page) for Bourbaki in 1954 by Samuel, a distinguished algebraic geometer and number theorist.
Alas, it is hard to conceive a worse timing for a book on algebraic geometry: one year later Serre would publish his paradigm shifting FAC, shortly followed by Grothendieck's theory of schemes, a vast development of Serre's article  (as acknowledged in the Preface to the EGA), which would forever change our vision of algebraic geometry.
Samuel's point of view is that of Weil: at the forefront is a "universal domain", a field extension $k\subset K$ with $K$ algebraically closed and of infinite transcendency degree over $k$.   
Geometry would happen in $\mathbb A^n(K)$ or $\mathbb P^n(K)$, whereas algebra and number theory would take place inside   $k[T_1,\dots,T_n]$ or $k[T_0,\dots,T_n]$.
A variety in Weil's vision could have a multitude of generic points, essentially points such that a polynomial vanishing on them must be zero.
It is quite moving to see the author  struggling with, for example, the product of varieties: he notices the difficulty due to the tensor product $E\otimes_k F$ of two field extensions $k\subset E,F$  having non-zero nilpotents but doesn't envision  incorporating these in his foundational text.
Grothendieck would soon show the world how considering nilpotents in the  very foundations of scheme theory would enrich and beautify algebraic geometry.  
I encourage every algebraic geometer to browse this nostalgic and unacknowledged witness of a bygone era of our beloved science.
Edit (May 27th, 2016)
Browsing the fascinating Grothendieck-Serre Correspondence ( a review of which is here) I found this excerpt from the very first letter of the Correspondence (page 3, dated January 28th, 1955), written by Grothendieck then in Lawrence, Kansas, USA  :    

"You said that Bourbaki wanted to send me a draft by Samuel on algebraic geometry (and commutative algebra?). I would be happy to get it..."   

This confirms that the document mentioned above was indeed authored by Samuel.
