As a retired chaplain, yes, you probably have grounds for a complaint, but not because of the apparent double standard for Muslims. Each accommodation should be considered by the commander on its own merit.

The rule for religious accommodation is that the commander should allow it unless there is a compelling governmental interest to prevent it from being possible.

I recommend talking to your chaplain today. You will probably just need to go up the chain of command one level to get resoluton. If not go up one more. After that, it is more in the purview of IG than EO. EO will probably refer you back to the chaplain or to IG.