Can I use the iPad mini 4 10W charger brick to charge my iPhone 6s?

I just upgraded my iPad mini to the 4 and it comes with a larger charging brick - it looks like a mini MacBook block charger and is labeled as 10W. Is it safe/compatible to use to charge my iPhone 6s? I would hate to ruin either one. Also, can I charge my iPad mini 4 with the standard chargers for iPhone 6s, 6, etc?