I've found that bokeh wall in some sources is referred as El Bokeh Wall. I wonder: why is that? Searching gives no answer. Is it in spanish or something else? Example of using "El Bokeh Wall": http://www.diyphotography.net/el-bokeh-wall/
Wild guess based on the fact that the the author is named Laya.
I wonder if "the El bokeh wall" -- which the author says is naming by himself
I call it “The El Bokeh Wall”
-- simply stands for "the effect given by a background wall where bokeh plays a predominant role made by someone whose name begins with L".
Note that the author is based in the Philippines where spanish is not unheard of, so it could well be a play on words.
I did some digging around on this and all the potential sources for the term 'el bokeh wall' appear to eventually lead back to that same article which suggests that the term was coined by the author.
Since Bokeh is Japanese and El would be Spanish/Portuguese, the etymology of those words doesn't lend support to the term being coined by a native speaker of either and there are previous examples of people using 'El' as an alternative for 'the old' as a reference to something familiar (as in to give them 'the old 1-2'.)
But... it's always worth dropping the author a line an seeing what they have to say.