A 5W LED bulb that's equivalent to a 100W incandescent bulb is not having its savings killed by a 1W computer.
100W * 5% * 24 Hours = 120Wh
1W * 24 Hours + 5W * 5% * 24 Hours = 30Wh
So it does depend on the duty cycle - As long as the 5W lightbulb with a 1W computer is used less than ~19 hours a day (80%) you'd still have savings:
1W * 24 Hours + 5W * 80% * 24 Hours = 120Wh