With load balancing, a Cisco device with something like RIP version 2 or EIGRP configured will load balance across 4 equal cost paths.
For bonded interfaces, that could be done in a Cisco device with PPP Multilink, but that must be configured on the provider side as well.
There is a difference between the two technologies. If you bonded them, but still wanted certain amout of bandwidth to be reserved for certain protocols (such as VoIP), then a bonded solution with QoS would work. It all depends on what you are trying to do...
Burt