If it makes you happy & feel closer to Guru , go for it.
Anything that brings you closer to your Guru , should be encouraged.
I dont think of any restriction that only a amritdhari can wear it.
But just keep in mind, whenever you wear chakar, your image will be uplifted in people minds and they will think of you as a great spiritual person because of your bana, so your each and every action will be scrutinized. In that regards you will have to be careful not to send off a wrong message or hurt anyone. When you wear a Bana, peoples expectations of you increase.