Are there any alternatives I could use to subscribe to platform events in lightning components?
My understanding is the only ways to monitor Platform events (as at Summer '17) is either via the Bayeux messaging protocol with cometd or via Apex triggers subscribed to the events.
In the Dreamforce 2016 Force.com and Heroku: Building a Connected System Through Platform Events there was a point on the Roadmap about "Additional messaging protocols" being supported. I heard the following from the youtube video and adjusted based on Google results - AMQP, MQTT, STOMP.
However, fast forward to TrailheaDx 2017 with Event Driven Architectures with Platform Events and it no longer shows up on the roadmap.
So, right now I think if falls into the forward looking statements category.
If you have a request for a specific messaging protocol or something more directly integrated with lightning, bring it up in the dedicated Official: Platform Events Chatter group or on ideas.