From the American Honey Plants Book:
I believe it to be only a pollen source.The blue lupine or bluebonnet (Lupinus subcarnosus) is widely distributed over southern and western Texas, fairly covering large areas when in bloom. The blooming period comes in March or April and the author heard many reports of this plant, as an important source of early honey when visiting Texas. Some claim it yields only pollen. Scholl lists it as a source of honey.