GPS in military mode and with a good missile *might* be good enough for destroying bridges. Still you would prefer something with multiple guidance modes working in cooperation.
Glonass in EWAR conditions? Yeah, sure, waste your smart munitions to do light damage to a bridge with near-misses.
The USN was able to hit Thanh Hoa just fine with crude "zeroth generation" joystick-guided AGM-12 Bullpups; the problem was that the Bullpups were just too small.
Sorry, but faith in RUSSIA STRONK is not a valid substitute for basic technical knowledge and common sense.
We do know that in terms of technical capabilities, GLONASS is not that different from GPS, and in at least some ways is less capable and obviously less invested in. By all chance, it's either equal or less capable, even if the differences are minor.
We also know that even certain third world countries can do GPS jamming since over a decade at least, with varying degrees of success.
Add up these two facts.
Why would you think that Ukraine, with years of potential preparation and likely western assistance, can't possibly do that to GLONASS?
Satellite communications are relatively low-powered systems so jamming them is relatively easy. The idea that GLONASS can't be jammed is hence completely ridiculous, especially since its specs are publicly known (most modern off-the-shelf GPS chips are actually hybrid GPS/GLONASS these days).
On the other hand, the thing about GPS / GLONASS guided missiles is that the satellite navigation is typically just used to update/enhance an inertial guidance system. Given that bridges are large, stationary targets, the INS guidance alone should be able to still score hits even with the satellite completely degraded.