In a BDSM relationship, both terms are used, but they don't reflect the same perspective.
Submission contract: Focused on the submissive, it highlights their commitment to submit. This is the most commonly used term, as it emphasizes the surrender of control and the duties of the submissive.
Domination contract: Focused on the Dominant, it stresses the active role of the one who leads. This term is less commonly used, but remains relevant when the emphasis is on the responsibilities and boundaries of the Dominant.
Some people simply refer to a D/s contract (Dominant/submissive) to stay neutral and inclusive.