I think it is interesting that in the data source from Bevo, even Blanco and Fayette counties have larger commuter ties to Travis than to Bexar. This speaks not of a minimal San Antonian influence, but of the outsize influence on the employment market that being a state capital can create.
Some others note:
Burnet is
this close to being considered in the Austin MSA according to that data.
Lee is also, much to my surprise, pretty darn close.
Blanco isn't quite as close to that threshold, but is definitely within reach over the next ten years.
Llano should definitely now be considered as part of Burnet's mSA (as I believed when the mSA was first created). As such, this would stave off the addition of Burnet into the Austin MSA for a few more years until Llano can develop a larger direct connection with Travis.
Within the next ten years all of these counties will certainly fall within the lines of Austin's CSA, while San Antonio will finally get the CSA with Kerrville that many here have hypothesized (the trend is certainly in that direction).
http://proximityone.com/demographics2020.htm
Developing these ideas further, Austin's anticipated CSA in 2020 will hold 2,399,472 while San Antonio's will hold 2,661,801.