Both dramas are based off webtoons that have the FL go back in time and get revenge on her husband/boyfriend and sister/best friend.

Perfect Marriage Revenge has:
FL is the adopted daughter of a wealthy family and she is mistreated by her mother.
After an accident and being killed by her mother, the FL wakes up and it is one year in the past.
She vows to get revenge on her family.
The ML and FL get together really early on and it's about them working together to get revenge.

Marry My husband has:
FL has cancer and not long left to live. She walks in on her husband cheating with her best friend. They kill her and she goes back in time 10 years.
She realises that everything is inevitable; if she avoids an injury, someone will get it somehow. This makes her realise that someone has to marry her husband and be killed by him.
She sets out to have her best friend to take her place.

Both dramas have similar vibes; they are both about mystical elements (ghosts or dreamworlds) set in a modern-day world.
The female leads in both dramas are tough, powerful and strong while both the male leads are introduced to a new world of either seeing ghosts or entering dreams.
If you like Hotel del Luna then you will like Mystic Pop-Up Bar and vice versa.