Does wireshark have a filter for TLS's Server Name Indication field?
Shawn E's answer is probably the correct answer but my wireshark version doesnt have that filter. Following filters do exists, however:
To check if the SNI field exists:
ssl.handshake.extension.type == 0
ssl.handshake.extension.type == "server_name"
To check if an extension contains certain domain:
ssl.handshake.extension.data contains "twitter.com"