The ROM is required by the Philippine Government and it legalizes an overseas marriage under Philippine Law. It is unimportant to the US Government or for US immigration purposes, other than it would be necessary if your wife wanted to change to your name prior to her visa, green card and social security card all being issued in her maiden name. If you plan on having little or no real interactions within the Philippines in the future, it is probably of little value and doesn't really matter. If the Philippines may play a more significant role in your future, such as if you want to retire there, own family property there, etc ect, it would be more important because it could affect your rights as a spouse of a Filipino citizen in the Philippines and might often come up in any kind of dealings with the Philippine Government.
Edit to add. The name changing aspect applies to CR1/IR1 cases. K1 applicants could just change their name during adjustment of status with a US Marriage Certificate so less important in K1 cases.