Questions I would ask if I were talking directly to you: What county/state placed you on probation, and for what offense? In what county/state did you just get arrested, and for what offense? Generally, getting arrested anywhere while on probation in Texas causes a motion to revoke probation, because all Texas probation departments have TCIC and NCIC access to computerized state and national arrest and warrant information. The best strategy to avoid a motion to revoke in this situation is to have an attorney either here or there proactively talk to your probation officer and attempt to paint your new case in the best possible light, focus on the merits and "fighting to clear your name" on the new case. You should talk one on one to a local attorney on this one as soon as possible.
If you do not report your arrest to your probation officer, you are probably violating your probation in another way. Please read the terms of your probation to see if you are required to report all contacts and / or arrests.
Prolonging the court date on the new case will not affect whether or not your probation officer learns of the arrest. Many offices run TCIC and NCIC records on a weekly or monthly basis to see if any of their probationers have been arrested. If Bexar County does this, then they will know regardless of whether the new case is final or not.
I assume you are on probation for DWI since you posted under DUI section. If you are a first offender, you are looking at up to 6 months in jail. If you are a second offender, then you are looking at up to 1 year in jail. If you are a subsequent offender, then it depends on if it was pled down or if it was a felony. In all cases in which a final conviction is rendered, you will lose your privilege to drive a motor vehicle - the length of time depends on the the history of convictions.
Hire a local lawyer who will have knowledge of how the system works in Bexar County, and how your judge thinks. It depends on many factors including what the offense for which you were arrested is.
You need to hire an attorney in the State you were arrested in and hope they don't contact your home state and inform your probation officer you were arrested.
It's possible the other state will not contact Texas and you can handle the case in the other state.
However, each time you leave the state of Texas you are immediately a fugitive from justice if you leave the state without permission from your probation officer.