If you use Link Aggregation (LACP), your total bandwidth doubles. However, 1 TCP session can only use one link. That means if you bundle 2x 10 Gbit, a VM can only use 1x 10 Gbit effectively for a single connection.
See:
https://www.cisco.com/c/en/us/support/docs/lan-switching/etherchannel/12023-4.html