Bonding VPN Tunnel and a Wireless Link

Hi, I’m still learning about Mikrotik so I’ve come here to learn.

We’ve got a building that it’s 2 kms far from our main office and they need to connect to our network for accessing servers and stuff. There’s a Wireless Link installed between both buildings but sometimes when there’s rain or snow it doesn’t work really well so also we’ve got an ADSL line to connect in case the wireless link cause problems.

My question is: Is there a way to bond both of theme and agregate bandwith? Or can I setup the ADSL line as a backup in case of failover?