It can receive any signal and transmit its signal if there is an ANTENNA, which must be outside, in an open area ABOVE THE GROUND. If the antenna fails, nothing will work without the antenna.
You can theoretically be able to catch something, but you are unlikely to understand anything, since the government communication is encrypted, and therefore you will not be able to contact the government. In fact, the question does not have an unambiguous answer, since it is not even clear who is in the bomb shelters: you, the government, or everyone. If you wanted to ask about broadcast messages for everyone, rather than establishing communication, then it should be noted that the most "long-range" communication is on long and medium waves, but how much I understand that in Russia transmitters in these ranges have not worked for a long time. As well as on short waves. The use of transmitters in even higher frequency ranges (VHF) will not help in this case, since they barely "look" beyond the horizon. However, it makes no sense to count on all these transmitters in the event of a large-scale military conflict, since all stationary radio communications will most likely be destroyed. In addition, there will be obvious power problems. You can rely only on the communications of the military, since they have a sufficient number of various rapidly deployable transmitting and receiving equipment with autonomous power supply. In addition, it allows you to work in different modes with different types of modulation, which allows both broadcasting messages for everyone and establishing communication. In principle, if the military begins to work on simple non-digital modulations in the open mode on the amateur bands, then it will be possible to establish communication with them using an amateur radio station. But you introduced into the equation a "bomb shelter", being in which will hardly allow you to stretch the cable from the transmitter outside and hang the antenna outside, unless the conflict will not be nuclear, and the bombing will have a break. And, of course, there must be an electric generator in the bomb shelter.