Yes. Here's what the FCC has to say about it:
http://www.fcc.gov/mb/audio/translator.html#NONFILLIN. It specifically says:
"Signal Delivery. Non-fill-in translators relaying commercial FM stations must receive the signal off-the-air, unless a waiver has been granted to feed a "white area" translator by other terrestrial means. A showing of the "white area" must be presented in the application requesting waiver of the signal delivery requirement.
Noncommercial educational non-fill-in translators operating on Channels 201 through 220 which are owned by the licensee of the primary noncommercial educational FM translator station may use alternate means to receive the primary FM station's signal. Non-fill-in noncommercial educational translators on Channels 221 through 300 are prohibited from any alternative methods of signal delivery, including programming feeds by satellite. See 47 CFR Section 74.1231(b). "
My guess is that 103.1 out of San Marcos translates KZAR 88.1 out of Gonzales. That's an Air 1 affiliate, and it would be feasible for them to pick up that station off-air, especially if they ran the antenna up the translator's tower.
As for 99.7, FCC records don't indicate they aired programming from Family Radio. According to the FCC, it aired programming from BBN, which would have probably been a relay of KYFS. Again, picking up KYFS off-air would be feasible in Austin if you run the antenna up the tower.