Let me start by saying I like Shiner and am not trying to knock their product(s).
But Shiner Bock isn't really a bock; it's more like an "amber/dark lager". It's not 100% true to style. For starters, it's not "big" enough (thanks to our silly Texas laws) to be a true bock. Most bocks fall in the 6-7%abv range. Shiner is 4.4%. I should note though, that I usually end up with a "smaller" bock than is typically true to style; I usually have 5.5-6.0% or so and I actually prefer this. I guess I should probably revise the grain bill down a bit in the recipe....
Shiner also uses corn in their grain bill which alters the final product.
So if I was to compare the two, I would say this recipe makes a beer that is:
similar in color to Shiner
about equivalent in bitterness and aroma (little to none)
has a fuller body than Shiner
is "smoother" than Shiner (in comparing the two, the use of corn will really jump out at you)
has more of a caramel, malty flavor to it
I usually carbonate to a lower level than Shiner
But, if your SWMBO likes Shiner, then it's safe to say she will like this beer. This beer isn't quite as sweet/malty as St. Arnold's Bock, but is more so than Shiner Bock.
Are you in B/CS? I haven't brewed in a while (building a new system), but I think I may have a bottle or two of this laying around if you'd like to try it.