1994 Cadillac EL Dorado Trunk lid - keyless or remote entry

Sounds like a trunk release solenoid may be at fault. The fact that the fuel door releases doesn't lead me to your valet switch, but check it anyway. If you know your way around a 12v test light, locate the solenoid connector(2 wire) in the trunk lid at the latch. Bridge the two wires with the test light and press the button. If it lights, you need a solenoid. A voltmeter will work as well, press button, see 12 volts, same result.