I’m guilty of it myself, of stuffing the receiver antenna into small fuselages wherever there is some room. Surprisingly, the 2.4 GHz signals are quite good at reaching the antenna. However, it is a fact, that this frequency band is line-of-sight and can’t bend around metal, carbon fibre, or similar material that is not transparent to the signal.
The servo wires are quite small in diameter and it is less likely that they may shield the signal. A completely different scenario is when the antenna is placed on the far side of a LiPo battery. Signals can and will be lost.
To prove the point, I placed an antenna underneath a battery and tried to bind a receiver to a transmitter. No such luck, the binding procedure was unsuccessful. Even with a bound receiver, the range was reduced to just a few metres.
Sometimes it is not easy to find a good place for the receiver antenna, but keep the above in mind when installing your electronic equipment.
By the way, EPO, EPP, fibreglass, balsa, and plywood are transparent to the radio signals. In other words, they won’t block the signal, but Kevlar, carbon fibre, and metal will.