Probably the most notably and theoretical commonality between these two texts is Deleuze and Guattari's notion of zones of indiscernibility [zones d'indiscernibilite] with Agameben's notion of zones of indifference ([zona d'indifferenza] which Heller-Roazen translates as zones of indetermination). For Deleuze and Guattari, the term doesn't just appear in that chapter, but throughout the book (with occasional variations on the term). Indeed, the first time the term is introduced in the book, Deleuze and Guattari write, "These zones, thresholds[.]". That by itself would be a striking relationship. However, also in the chapter of geophilosophy Deleuze and Guattari turn briefly to the question of the camp, and in so doing turn to the work of Primo Levi, wherein they specifically bring up the gray zone. Also, in that chapter, you can see a sustained critique of the notion of human rights. This strange relationship of a zone of indiscernibility/indifference, is just a jumping off point.
We probably all know of the two most sustained engagements with Deleuze's thought in the work of Agamben. In the essay "Absolute Immanence" Agamben deals directly with Deleuze's thought (and anyone interested in exploring more on the relationship of bare life and the animal in Agamben's work should also turn to this essay). The other place is on Agamben's truly stunning essay "Bartleby, or On Contingency" which was published originally along with the Italian translation of Deleuze's "Bartleby, or The Formula." This latter essay by Agamben deals with Deleuze's work only tangentially, which seems to be the most common way that Agamben seems to ever deal with Deleuze.
This tangential way can perhaps be seen in two of the essays contained within the recent translation What is an Apparatus? and Other Essays. In "The Friend" Agamben writes in the opening paragraph:
It is certainly with a somewhat archaizing intent, then, that a contemporary philosopher-- when posing the extreme question "What is philosophy?"-- was able to write that this is a question to be discussed entre amis, between friends.
This philosopher was clearly Deleuze and Guattari (I never know what to about the turning of these plural thinkers into simply Deleuze, it always seems absurd to me). Perhaps even more oblique is the reference in "What is an Appuratus?". The title of that essay is, first of all, the same as a title of an essay by Deleuze on Foucault. Moreover, we see that strange sort of reference again in the second sentence of the essay, "As a philosopher for whom I have the greatest respect once said, terminology is the poetic moment of thought." This is also a clear reference to Deleuze, who made this claim in one way or another in several places. Including, again with Guattari in What is Philosophy?, "In each case there must be a strange necessity for these words and for their choice, like an element of style." And in this essay, which takes its name from Deleuze, and who is reference in the opening lines, is never mentioned.
Right now, I don't really have a point I am trying to make. Just some reflections.