This paragraph seems a bit misleading:
While thrust faults that reach the surface (such as the
infamous San Andreas) are more easily studied, blind-thrust
faults -- buried faults that terminate underground before
breaking the surface -- are no less important to geologists
and have been responsible for a recent string of destructive
quakes. - the San Andreas is not a thrust fault....

Also I couldn't find any info at the Southern California Data Center about a Puente Hills Fault. They are usually pretty good about keeping things updated. I did find a reference to it on the WHittier Narrows earthquake page.

My guess is we can probably predict for that fault as well as any other faults... As far as I can tell there should be some sort of precursor as it would be a shallow quake. But the truth is we just don't know yet with certainty about any predictions - we're trying though!

Here's some more info from EQE - http://www.eqe.com/revamp/puente.htm (this should ease your mind a bit - this is just a portion of the article - the entire article is very good)
Given the evidence presented by Shaw and Shearer, the Puente Hills Thrust clearly exists. However, the authors have to make many assumptions to postulate its downward extent and its potential seismogenic capability. The fault is only defined to a depth of about 5 to 7 kilometers in the seismic profiles. At this point, the fault is confined to upper Tertiary-age sediments that are not believed to be seismogenic based on past earthquakes. They must extrapolate this fault to the depth of the Whittier Narrows earthquake to project it into harder rock which is believed to be capable of generating a significant earthquake. Furthermore, only part of the Sante Fe Springs segment is defined to this depth, making the projection of the other segments to seismogenic depth even more speculative. Given such a limited seismogenic rupture surface, the potential magnitude that this fault system could generate, even if extrapolated to the depth of the Whittier Narrows earthquake, would be smaller than the authors indicate.
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More info can be found here: http://tectonics.harvard.edu/sgat/SGATfault.html - with a fault map ( a little difficult to make out)

Canie