Bem, eu percebi isso. Funcionou assim:
case node['hostname']
when 'server1' && 'server2'
template "template1.conf" do
source "template1.conf.erb"
owner "root"
group "root"
mode "0644"
end
else
template "template2.conf" do
source "template2.conf.erb"
owner "root"
group "root"
mode "0644"
end
end