Mealy bugs on one (so far) of my orchids

[samantha.c]

I noticed what looked like cobwebs on one of my dendrobium a few days ago, but didn't think much of it at the time. Today I looked closer and saw that it was the sticky substance from what I think are mealy bugs. This is one of the plants I've had the longest and it's kept a in the middle of most of my plants. I removed the bugs I could see. I was worried one fell into a neighboring schomburgkia so I took that and the dendrobium and sprayed them both down with neem oil. I plan to keep them isolated for a bit and see how they do.

I'm wondering...is neem oil sufficient and do I need to treat all my plants? Also, should I be repotting? I want to get ahead of this now and am hoping not to lose plants.