Yes, typically you will need to wear your post-operative compression garment to bed for at least the first three to four weeks. For major procedures likes tummy tucks and body lifts, you will need to wear it full time for four weeks, including when you sleep. You can take the garment off to go to sleep on weeks 5-6.
There is no harm in wearing the compression garment longer or more often than recommended (including at bedtime). The length of time you will need to wear a post-operative compression garment or bra may vary; always follow your surgeon's instructions.