tl;dr - You should, wherever possible, use tor on the local system. Especially when the "local" network is potentially hostile (which is almost always with wireless). If you can run Tor Browser on the laptop and just use the phone as a hotspot, prefer that option! And avoid running Tor-over-Tor, allow the laptop to connect directly to the internet through the hotspot and run Tor Browser as normal.
"Personal" Wireless (
WPA2-PSK) does not provide forward-secrecy. This means a local adversary who takes the time to log all of your packets and manages to capture the WPA2 4-way handshake will be able to (with effort dependent on the strength of your passphase) break your WPA2
Pre-shared Master Key, derived from the passphase) and once they have this they can derive the
Pairwise Transient Key, or session key which is used to encrypt your traffic) for all previous and future WPA2 sessions for which they have also captured the 4-way handshake, assuming the same
PMK. This is because the
PTK is derived from values visible to an observer during the 4-way handshake with the exception of the
PMK, which is the only unknown value.
Note that the traffic that they would be able to capture and decrypt in that case would be the traffic before any of Tor's protection is applied. They will see exactly what content you are sending and where, it will not be anonymized. It may be encrypted at the application layer (e.g.
ssh, or other
tls protected transports) but that may still constitute a catastrophic failure for your anonymity.
A tor circuit is protected with authenticated, end-to-end, forward-secret encryption so as a client you should always prefer to have your apps be as close as possible to your tor client to gain the most out of the protections provided by this property.
Also you should never ever entrust
WPA2-PSK as anything but a weak means of access control, the cryptography just isn't up to scratch.