I've been shooting Potra 160 in 35mm at ISO 800 and let the lab do only +1 push development, meaning development at ISO 320. So underexposure was comparable. I took shots of a music events and some on an automotive exhibition. The negs came back a bit dark, but nothing that a good scanner could not handle.
Your shots will probably be fine even if you do not compensate for it in development.
You underexposed by a full two stops. (I consider 160 film to REALLY be 100 film.) Thus you need to over develop by about 25% - 33%, or a bit more. You will attain decent highlights but shadow detail will be pitiful. But, honestly, you should have little problems with color-crossover and might be surprised with how great your highlights look. Midtones will be OK but not ideal. - David Lyga
A push development will increase the contrast, but won't make any meaningful difference with respect to shadow detail.
If the nature of the light and the subject are such that an increase in contrast might help, then go ahead and order a one stop "push".
If, however, your shots include a lot of highlight flesh tones and human features, you may prefer to leave the contrast unchanged, knowing that the "near shadows" will lack contrast.