BGP Neighborship query

Can we able to advertise GRE or IP Sec Tunnels in BGP?
I can see where I am working this type of configuration.

Please help me to understand the configuration.

I can see the below configuration:
router#sh int tu4
Tunnel is using Zayo ISP Circuit.
Protocol: Tunnel protocol/transport IPSEC/IP

router#sh ip bgp nei x.x.x.x
BGP neighbor is x.x.x.x, remote AS xxxx, external link
Description: Destination Router Tunnel Number
BGP version 4, remote router ID
BGP state = Idle, down for never
Configured hold time is 15, keepalive interval is 5 seconds
Minimum holdtime from neighbor is 0 seconds
Last update received: n/a
Neighbor sessions:
0 active, is not multisession capable (disabled)
Stateful switchover support enabled: NO
Do log neighbor state changes (via global configuration)
Default minimum time between advertisement runs is 30 second