Yes the two seem similar from the photos. But is Stein's Pillar also basalt? Anyway I should do a new google research on the climb of Roque Nublo. I was somewhat disappointed with what I got as return earlier this year. It's the national landmark of Gran Canaria and a very popular climbing destination so there must be more.
The routes appear to be heavily bolted. The guy we saw (and cheered) climbing found a bolt every 5 ft. They seemed to be new and solid. Anyway - he cheated - used the bolts to draw himself up. Spaniards! ;-))